I have been researching 700HP small block Chevy engines.
Got me thinking before I go ahead and drop one these bad boys in my 1967 Parisienne convertible perhaps I should see if I have a posi or limited slip rear end.
( I can't afford to keep replacing one tire all the time)
What and where are the rpo codes to check?
CdnGMfan said
Mar 20, 2015
You should get the axle code from the rear axle tube. Stamped on the axle tube to the left or right of the "pumpkin" will be a code. It will read something like "DA 0212 B" which will break down as follows: DA Open 3.08:1 ratio, 0212 Feb 12, B Buffalo. I dont have a complete list of all 1967 codes but it will be a start. Perhaps someone can supply that info after you find it and post it here.
Technically the RPO code for Positraction is G80, but it wont appear on your trim tag. If you have GM documentation (VVS) it will list the options your car left the factory with.
If you are planning on dropping a 700-horse SBC into your Parisienne you should plan on a stronger rear if it isnt a 12-bolt. That kind of power out of a small block is pretty radical and would have to spinning pretty tight to make that kind of power. I suspect that your gearing will need to change to a much higher number. A small displacement engine making power like that will not be a relaxed engine, it will be high-strung and need to keep the revs up. The greater the displacement, the greater the torque, IRRESPECTIVE of horsepower. Moving a big car will take torque, or if not torque then lots of revs and gearing.
SGS Welding said
Mar 20, 2015
Canadian GM fan
Thanks for the good info
As far as the 700 hp engine I was joking
I am dreaming of 350hp someday and just want to be ready for when that happens
I have never worked on a rear end
Is it easy or possible to turn a regular rear end into a posi or limited slip?
Or should I find a posi and switch out the whole rear?
koolconvertible said
Mar 20, 2015
I recently installed a posi in my 65 parisienne 12 bolt to handle extra power for my big block. I bought the posi unit and took it and the complete diff housing drum to drum to a reco shop who did the complete job. If you search the threads here you will find a member has recently done just that himself with pictures. If you plan on power increases and have the dough to do this, it is the best way to get that power to the ground along with other drivetrain improvements.
427carl said
Mar 20, 2015
Always interesting....
I would like some more "urge" up through the gears... My 4200 lb sled had 3:36 posi and 27 inch tires and now has 2:73 open and 29 inch tires
I can't find anyone around here, to "just put" a set of gears in for me...
They all want to sell me a posi. unit, which I don't want .... as I don't race my old cars, so don't see the need for a heavy 325hp car...
anyway, not to derail
700 HP should be OK in a 12 bolt on the street.... as long as you don't put "sticky" tires, on it , you wou'nt brake it
Heres a photo from April 2006 My friend suggested that I check out the torque of the 468 big block..... One of my best memories... too bad the road curved, I think I could have spun it for 1000 ft
I have never worked on a rear end assembly but from what I understand it is a matter of setting preload on the crush sleeve and setting the backlash so the ring & pinion mesh properly. Yes, you can upgrade your rear to limited slip. There are several manufacturers that make limited slip differentials to drop in. Theres Powertrax, Auburn and Eaton to name a few. I recommend the Eaton because they are rebuildable while the Auburn is not. Eaton uses clutches to lock; some others use a ratchet mechanism. Eaton was GM's OEM supplier for posi.
Changing your ratio is doable, but if you are running a 3-series ratio then you can work within ratios from 3.08 through 3.70. It is also possible to run 4-series gears but it is not recommended unless you already have a 4-series carrier. If you utilize a 3-series carrier for gearing in the 4-series range you end up using a ring gear spacer to keep the ring gear in contact with the smaller pinion gear. That is not good as the thickness of the ring gear and added spacer put too much strain on the carrier bolts. I would fully expect your 67 to have a 3.08 rear unless your car is running a TH400 from the factory (2.73 gearing). What engine & trans did your car come with originally? Typically they came with 283 Powerglides.
If you want some real feedback on upgrading your cars rear, I recommend searching at Team Chevelle. There are several people there that rebuild rear ends every day and they can give great recommendations. Theres a guy over there named Big Gearhead that can give you all the straight scoop you could ever want.
-- Edited by CdnGMfan on Friday 20th of March 2015 07:32:04 PM
427carl said
Mar 20, 2015
CdnGMfan wrote:
I have never worked on a rear end assembly but from what I understand it is a matter of setting preload on the crush sleeve and setting the backlash so the ring & pinion mesh properly. Yes, you can upgrade your rear to limited slip. There are several manufacturers that make limited slip differentials to drop in. Theres Powertrax, Auburn and Eaton to name a few. I recommend the Eaton because they are rebuildable while the Auburn is not. Eaton uses clutches to lock; some others use a ratchet mechanism. Eaton was GM's OEM supplier for posi.
Changing your ratio is doable, but if you are running a 3-series ratio then you can work within ratios from 3.08 through 3.70. It is also possible to run 4-series gears but it is not recommended unless you already have a 4-series carrier. If you make a 3-series carrier for gearing in the 4-series range you end up using a ring gear spacer to keep the ring gear in contact with the smaller pinion gear. That is not good as the thickness of the ring gear and added spacer put too much strain on the carrier bolts. I would fully expect your 67 to have a 3.08 rear unless your car is running a TH400 from the factory (2.73 gearing). What engine & trans did your car come with originally? Typically they came with 283 Powerglides.
If you want some real feedback on upgrading your cars rear, I recommend searching at Team Chevelle. There are several people there that rebuild rear ends every day and they can give great recommendations. Theres a guy over there named Big Gearhead that can give you all the straight scoop you could ever want.
Thanks car is a 66 B-Body with 396 stick was 3:36 new in 50 years, rear either was swapped or posi and 3:36 taken out
I see a fellow from Chatham who advertises 12 bolt parts.. I will see if he will work on it w/o a posi
I won't pay 10cents extra for a posi I would never need it in my short lifetime I think 3:55's would give it the go I want ....(its not a race car)
SGS Welding said
Mar 20, 2015
427carl
I think you should consider a posi
If you do the beanfest tour it's cooler to burnout both tires.
Spectators on both sides of the street deserve to see tires turning to smoke!
Lol
Besides if your the Carl I think you are tires should still be easy to get!
Thanks again Canadian gm fan
Your good info has me on the right track.
SGS Welding said
Mar 20, 2015
The car came with a 327 2 speed powerful glide.14 inch tires 12 bolt rear end.
427carl said
Mar 20, 2015
SGS Welding wrote:
427carl I think you should consider a posi If you do the beanfest tour it's cooler to burnout both tires. Spectators on both sides of the street deserve to see tires turning to smoke! Lol Besides if your the Carl I think you are tires should still be easy to get! Thanks again Canadian gm fan Your good info has me on the right track.
That ok... I always skip the tour ... too many fellows driving, after have many many beers....
Someone will install some gears for me I'll install a posi, if someone gives me one for free
57 Pathfinder said
Mar 20, 2015
Look into the True-Trac. It's an all gear limited slip, no clutches to wear out. It's also very smooth and 'invisible' during normal driving, but it works very well when the tires break loose. My other vehicular addiction in K5 Blazers, and I've run several different traction aids in those. Spool, Detroit, and Eaton's explosion prone Gov-Lock. A spool is ugly for anything other than ensuring full power to both wheels all the time...the Detroit was much more civilized, just a little 'locker steer' when shifting and it could be a bit noisy. The Gov-Lock...click, click, boom! lol
Anyways, I've heard nothing but good on the True-Trac for street vehicles.
The crush sleeve is a pain in the arse, but they do make a crush sleeve eliminator for the 12 bolt. Something to look into if you're re-gearing yourself.
427carl said
Mar 20, 2015
57 Pathfinder wrote:
Look into the True-Trac. It's an all gear limited slip, no clutches to wear out. It's also very smooth and 'invisible' during normal driving, but it works very well when the tires break loose. My other vehicular addiction in K5 Blazers, and I've run several different traction aids in those. Spool, Detroit, and Eaton's explosion prone Gov-Lock. A spool is ugly for anything other than ensuring full power to both wheels all the time...the Detroit was much more civilized, just a little 'locker steer' when shifting and it could be a bit noisy. The Gov-Lock...click, click, boom! lol
Anyways, I've heard nothing but good on the True-Trac for street vehicles.
The crush sleeve is a pain in the arse, but they do make a crush sleeve eliminator for the 12 bolt. Something to look into if you're re-gearing yourself.
Thank you.... I do not want a posi.. posi-track- limited slip, or True trac don't want to spend the money on it...
Its totally useless... for a car that never see the track... OPP around here will tow it away, and you walk home, if you do 130 km in a 80.....
Car never races... I just want a little more passing power I'll get someone, somewhere to JUST add some gears... or I will leave it alone Last year I drove the car almost 50 miles....
57 Pathfinder said
Mar 20, 2015
Sorry Carl, that was aimed at the original poster, not you. I should have quoted the original post to be more clear. My bad.
-- Edited by 57 Pathfinder on Friday 20th of March 2015 10:58:12 PM
koolconvertible said
Mar 21, 2015
As with all car mods, they are an individual choice and preference Depending on many factors. all our cars are fun to drive and enjoy because they are ours and we built them how we wanted to! I love and appreciate em all! Except goggomobiles, they are hard to love.....
64PARCONUK said
Mar 21, 2015
427Carl
Here's proof my daily driver can (almost) fly. Also, two stripes without a posi, I never managed that before.
I have had over 100 muscle cars in 48 years and love the power and smoke too
BUT
I live in a world of enforcement, which makes it too risky to run a car like I used too....
Drag racing is too competitive (for me) and too long a event...(sitting in 80-90 degree) heat in a old car for hours waiting for 2-3 runs is not fun for me
I just want a little more power up through the gears... big block and heavy car need torque.... but I am on a budget, and a posi would be such a waste for me...
The money for a posi will buy me fuel for 2 summers maybe 3
koolconvertible said
Mar 21, 2015
427carl wrote:
Nice burnout... I love them and used to do them
I have had over 100 muscle cars in 48 years and love the power and smoke too
BUT
I live in a world of enforcement, which makes it too risky to run a car like I used too....
Drag racing is too competitive (for me) and too long a event...(sitting in 80-90 degree) heat in a old car for hours waiting for 2-3 runs is not fun for me
I just want a little more power up through the gears... big block and heavy car need torque.... but I am on a budget, and a posi would be such a waste for me...
The money for a posi will buy me fuel for 2 summers maybe 3
Respect!
cdnpont said
Mar 22, 2015
If you're planning on putting big power to your big 67. Then first focus ALL your early budget on handling and braking.
Adding big power to our wallowing barge is a recipe for disaster imop. Make it totally safe first, then build a rear, trans and driveshaft that can handle some torque, then plug in the power and play! I'm currently building a 496 that should produce around 580/600, so I still need some serious work to be done. My saving grace is I'll likely never get grip, so things should tend to survive a little better that way.
Oh, and rear ends can absolutely be built in a backyard shed with just a few simple tools and skills. If I can do it, anyone can. I successfully converted my open 12 bolt, to a Eaton posi with a 3.55:1. And so far so good.
But there is step by step help available from the good members here if you ever need it.
Cheers,
koolconvertible said
Mar 27, 2015
cdnpont wrote:
If you're planning on putting big power to your big 67. Then first focus ALL your early budget on handling and braking.
Adding big power to our wallowing barge is a recipe for disaster imop. Make it totally safe first, then build a rear, trans and driveshaft that can handle some torque, then plug in the power and play! I'm currently building a 496 that should produce around 580/600, so I still need some serious work to be done. My saving grace is I'll likely never get grip, so things should tend to survive a little better that way.
Oh, and rear ends can absolutely be built in a backyard shed with just a few simple tools and skills. If I can do it, anyone can. I successfully converted my open 12 bolt, to a Eaton posi with a 3.55:1. And so far so good.
But there is step by step help available from the good members here if you ever need it.
Cheers,
Agreed, have upgraded suspension and brakes to handle my fatty! Just finished brakes today. Dual circuit, late model Gm booster, big discs front, modified rear cylinders amongst other things, suspension upgrades, nice beefy turbo 400....all in ll should make for a nice package!
You should get the axle code from the rear axle tube. Stamped on the axle tube to the left or right of the "pumpkin" will be a code. It will read something like "DA 0212 B" which will break down as follows: DA Open 3.08:1 ratio, 0212 Feb 12, B Buffalo. I dont have a complete list of all 1967 codes but it will be a start. Perhaps someone can supply that info after you find it and post it here.
Technically the RPO code for Positraction is G80, but it wont appear on your trim tag. If you have GM documentation (VVS) it will list the options your car left the factory with.
If you are planning on dropping a 700-horse SBC into your Parisienne you should plan on a stronger rear if it isnt a 12-bolt. That kind of power out of a small block is pretty radical and would have to spinning pretty tight to make that kind of power. I suspect that your gearing will need to change to a much higher number. A small displacement engine making power like that will not be a relaxed engine, it will be high-strung and need to keep the revs up. The greater the displacement, the greater the torque, IRRESPECTIVE of horsepower. Moving a big car will take torque, or if not torque then lots of revs and gearing.
I recently installed a posi in my 65 parisienne 12 bolt to handle extra power for my big block. I bought the posi unit and took it and the complete diff housing drum to drum to a reco shop who did the complete job. If you search the threads here you will find a member has recently done just that himself with pictures. If you plan on power increases and have the dough to do this, it is the best way to get that power to the ground along with other drivetrain improvements.
Always interesting....
I would like some more "urge" up through the gears... My 4200 lb sled had 3:36 posi and 27 inch tires and now has 2:73 open and 29 inch tires
I can't find anyone around here, to "just put" a set of gears in for me...
They all want to sell me a posi. unit, which I don't want
.... as I don't race my old cars, so don't see the need for a heavy 325hp car...
anyway, not to derail
700 HP should be OK in a 12 bolt on the street.... as long as you don't put "sticky" tires, on it , you wou'nt brake it
Heres a photo from April 2006 My friend suggested that I check out the torque of the 468 big block..... One of my best memories... too bad the road curved, I think I could have spun it for 1000 ft
I have never worked on a rear end assembly but from what I understand it is a matter of setting preload on the crush sleeve and setting the backlash so the ring & pinion mesh properly. Yes, you can upgrade your rear to limited slip. There are several manufacturers that make limited slip differentials to drop in. Theres Powertrax, Auburn and Eaton to name a few. I recommend the Eaton because they are rebuildable while the Auburn is not. Eaton uses clutches to lock; some others use a ratchet mechanism. Eaton was GM's OEM supplier for posi.
Changing your ratio is doable, but if you are running a 3-series ratio then you can work within ratios from 3.08 through 3.70. It is also possible to run 4-series gears but it is not recommended unless you already have a 4-series carrier. If you utilize a 3-series carrier for gearing in the 4-series range you end up using a ring gear spacer to keep the ring gear in contact with the smaller pinion gear. That is not good as the thickness of the ring gear and added spacer put too much strain on the carrier bolts. I would fully expect your 67 to have a 3.08 rear unless your car is running a TH400 from the factory (2.73 gearing). What engine & trans did your car come with originally? Typically they came with 283 Powerglides.
If you want some real feedback on upgrading your cars rear, I recommend searching at Team Chevelle. There are several people there that rebuild rear ends every day and they can give great recommendations. Theres a guy over there named Big Gearhead that can give you all the straight scoop you could ever want.
-- Edited by CdnGMfan on Friday 20th of March 2015 07:32:04 PM
Thanks car is a 66 B-Body with 396 stick was 3:36 new in 50 years, rear either was swapped or posi and 3:36 taken out
I see a fellow from Chatham who advertises 12 bolt parts.. I will see if he will work on it w/o a posi
I won't pay 10cents extra for a posi I would never need it in my short lifetime I think 3:55's would give it the go I want ....(its not a race car)
That ok... I always skip the tour ... too many fellows driving, after have many many beers....
Someone will install some gears for me I'll install a posi, if someone gives me one for free
Anyways, I've heard nothing but good on the True-Trac for street vehicles.
The crush sleeve is a pain in the arse, but they do make a crush sleeve eliminator for the 12 bolt. Something to look into if you're re-gearing yourself.
Thank you.... I do not want a posi.. posi-track- limited slip, or True trac don't want to spend the money on it...
Its totally useless... for a car that never see the track... OPP around here will tow it away, and you walk home, if you do 130 km in a 80.....
Car never races... I just want a little more passing power I'll get someone, somewhere to JUST add some gears... or I will leave it alone Last year I drove the car almost 50 miles....
Sorry Carl, that was aimed at the original poster, not you. I should have quoted the original post to be more clear. My bad.
-- Edited by 57 Pathfinder on Friday 20th of March 2015 10:58:12 PM
As with all car mods, they are an individual choice and preference Depending on many factors. all our cars are fun to drive and enjoy because they are ours and we built them how we wanted to! I love and appreciate em all! Except goggomobiles, they are hard to love.....
427Carl
Here's proof my daily driver can (almost) fly. Also, two stripes without a posi, I never managed that before.
Nice burnout... I love them and used to do them
I have had over 100 muscle cars in 48 years and love the power and smoke too
BUT
I live in a world of enforcement, which makes it too risky to run a car like I used too....
Drag racing is too competitive (for me) and too long a event...(sitting in 80-90 degree) heat in a old car for hours waiting for 2-3 runs is not fun for me
I just want a little more power up through the gears... big block and heavy car need torque.... but I am on a budget, and a posi would be such a waste for me...
The money for a posi will buy me fuel for 2 summers maybe 3
Respect!
If you're planning on putting big power to your big 67. Then first focus ALL your early budget on handling and braking.
Adding big power to our wallowing barge is a recipe for disaster imop. Make it totally safe first, then build a rear, trans and driveshaft that can handle some torque, then plug in the power and play! I'm currently building a 496 that should produce around 580/600, so I still need some serious work to be done. My saving grace is I'll likely never get grip, so things should tend to survive a little better that way.
Oh, and rear ends can absolutely be built in a backyard shed with just a few simple tools and skills. If I can do it, anyone can. I successfully converted my open 12 bolt, to a Eaton posi with a 3.55:1. And so far so good.
But there is step by step help available from the good members here if you ever need it.
Cheers,
Agreed, have upgraded suspension and brakes to handle my fatty! Just finished brakes today. Dual circuit, late model Gm booster, big discs front, modified rear cylinders amongst other things, suspension upgrades, nice beefy turbo 400....all in ll should make for a nice package!
Smart upgrade Phil.