thanks for taking a view..I have a 73 GP  with a 400 I'm the 2nd owner and it has only 48,000 miles Im just wondering what i could do to wake her up a bit any suggestions are appreciated

Welcome aboard!

welcome aboard from sudbury ontario! a cam is always a good performance upgrade. nice car !

Welcome "big James" yep & CAM will help but 1st. check out those gears out back. You likely have a set of HWY. gears & no cam will help that!!! I assume that the 400 is the American Block??? If so, I'd be doing the timing chain & gears there when you put a new "BUMP STICK" in it. These engines are "bad" for streached chains & jump a few teeth!! [Don't ask,been there done it & NO TEE shirt] Hope you have a "warped sense of humour" as most of us are a "little off the wall" here!!!!!

Thanks for the welcoming

Welcome BigJames ! My brother had a 73 SJ 455 and I loved that car. Great second gear rubber from a bone stock TH400 car. Keep us posted !

Welcome from Winnipeg BigJames .

Welcome. It would depend on $ to spend. Start with the rear end. If hwy gears and no posi, then that's where is I'd start. Then cam, heads, intake, headders, etc... Don't forget to put a shift kit in the 'ol turbo 400 as well. Remember to do the bottom end of your mill as well. Big block ponchos don't like to rev ovr 5500-6000 rpm's. They eat camshafts after that.

i think there hwy gears on her so im putting new gears nest week, what would you recommend?

bigjames wrote:

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i think there hwy gears on her so im putting new gears nest week, what would you recommend?

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next week!   new gears!    you have moved to Calgary   gas is cheap.. no taxes...  Try 4:10     that will "wake it up"    

Welcome to the site......

 

Welcome to the forum BigJames... Good to have you here with that sweet car... Cheers

a 323 or a 355 is a nice all around gear. 355 being more of a saturday night specieal.

is the 355 better then th 410?

410 is a 1/4 mile gear, 294 or 308 is prolly what you have. the bigger the # the more it will rev. sounds like you are a cruiser kinda guy, that like to play, once in a while, so i think a 323 or a 355 on the high side would be good for you. colin oates

Welcome bigjames, Sweet ride, cars in that condition are few and far between.

sweet so im dropping the car off next week and im going for the 3.55 thanks everyone do you think headers would be wise after the gear change out

think of the gears as sprockets on the rear of a muti-geared bicycle. the larger the sprocket, more teeth the higher the gear. the larger rear sprocket is easier to go faster, quicker but loose out on top speed. the smaller sprocket is for top end cruising but a lot slower to get there. clear as mud. 273 econo gear, good for highway cruising, but slow on the take off. 308 better all around but not really quick on the take off 355 quicker take off but engine spins faster and uses more gas 411 called 1/4 mile gear, not good for the highway engine will whine at speed anything higher is for racing bottom line is how fast do you want to go and how much gas do you want to burn, years ago i had a bike that i went over the top. went up 7 teeth on the rear and down 2 on the front. really quick on the take off but i had to shift by the time i cleared the intersection and the motor was winding out at a 100 MPH.

how hard is it to change them myself, is there any more hardware id need to buy

not something usually done by a backyard mechanic. vaguely recall something about setting the backlash. you will need a dial indicator.

If you are talking about doing the gears yourself.They need tobe set up properly if not, you will get a wine out of them.Some times you get a wine anyways,but there is a way to set them up.My buddy has a transmission shop and he puts a guage on gears to set them up and paint to check the wear pattern.There is more to it then you would think.If your doing the gears you should put in a bearing kit change the axle seals and get your axles looked at for pitting.If you are going to do it, you might as well do it right the first time.As for your choice of gears I would agree with the 355's or 373's If you have a 15 inch tire it will make a difference in your RPM also.I had 308, 373,410, 456's my 373's are the all around gear that gives your car alittle back bone on the street and lets you go on the highway.Good luck

what are diffrence between the 355 and 373 i am looking to be able to drive on the hwy and pick and go aswell thge 410 are to much for what i want

how much driving do you do on the hiway?I find 373 A bit low on the hiway around 110k but good at 90k it depends what you are doing.You could also get a overdrive trans.....

i live in calgary so im very close to the hwy i drive it daily in the summer im not sure what ones to buy im deciding between the 3.55, 3.73, 3.90, 4.10

-- Edited by bigjames on Thursday 30th of December 2010 09:36:40 PM

i think the 355,s will fit the bill just right for the driving style you,ll be doing. anything bigger than that will just kill in gas mileage. the 355,s with that big ol 400 should light those tires up pretty good, but still be tame on the hwy.

Welcome aboard.