I have a neat 80 Grand Prix LJ with 4.9L, purchased last July and has been in storage since. Very good shape as it is from Alberta with only 76000Km on it. My question, what is the best way to get more power from this 301 - keeping it stock? These cars were always a bit lazy on takeoff. I had an 80GP over 20 years ago but totalled it in a moose collision, peeled the roof off her - vowed if I ever see another in good shape I'd have her
You can find upgrades from Edelbrock and those places but best idea is to get a Pontiac 400 and bolt that in, goes like stink OR find a better rear axle ratio, you have some crazy ratio like 2.29: 1. I had an 80 GP W37 301 and I always liked that car, had an unlimited top end.
The 400 idea is much better. If you have ever seen the ports in a 301 you will quickly understand why money spent on performance updates on it is a waste.
__________________
1966 Strato Chief 2 door, 427 4 speed, 45,000 original miles
1966 Grande Parisienne, 396 1 of 23 factory air cars
The Hook The downsized Grand Prixs of this era shed 500 pounds when compared with their predecessors, and they retained Pontiac style.
Advantages They are lightweight, plentiful, and cheap on the used-car circuit. Grand Prixs of this vintage make affordable and unique race cars as well.
For 1978, the 301 2V was standard in the upscale LJ, and a 4V version was optional. California got a 305 Chevy with a 4V. If you keep the 301, you can add the four-barrel intake and carb and upgrade the exhaust, jetting, and ignition to provide spirited, if not dizzying, performance. The 305 Chevy engine is easily and inexpensively upgraded.
In 1979, the 301 four-barrel was offered with a four-speed manual trans-rare to be sure, but a cool find nonetheless.
A Chevy 305 was offered from 1983 to 1987. In 1984, the famed 200-4R overdrive trans was available with eight-cylinder engines.
These cars have great swap potentia. A '70-up 350, 400, or 455 Pontiac will bolt right in with proper mounts and brackets.
Disadvantages A V-6 was the standard engine for the entire run. The Oldsmobile 350 diesel-equipped Grand Prix of 1981-1985 was a poor performer. Don't buy one unless you're planning an immediate engine swap or want to take advantage of the Olds diesel's super-thick cylinder walls to build a big-inch Olds gasoline engine. In 1980 and for 1981, the 265 Pontiac 2V engine became standard in the LJ; just when you thought Pontiac couldn't build a V-8 with less power, here was one with 120 hp. So don't assume a 301 is under the hood of your prospective '80-'81 purchase. It might be in an '80 since both were offered, but in 1981 the only Pontiac engine was the 265. No V-8 gasoline engine was available in 1982.
Standard wheel size was once again 14 inches, down from 15. Rear-gear ratios ran as low as 2.29:1 and many were 2.41:1 or 2.73:1, so a gear swap is necessary if more performance is desired-unless you plan to run at the Salt Flats.
Swapability You can easily install a '70-up traditional Pontiac engine in the A-special (A/G hybrid) '78-'81 models and do the same using a B-O-P-pattern, bellhousing-equipped, Turbo 350 transmission and '78-'81 Pontiac motor mounts in any '82-'87 G-body (check local emissions laws, however). The 12.7:1 steering box from a Buick GN-/T-Type, Olds 442/Hurst, Chevy Monte Carlo SS, or the '86 Pontiac 2+2 Grand Prix is a direct bolt-in to the G-body Grand Prix, as are their 1.25-inch front and 0.875-inch rear stabilizer bars. Traditional 15x7 Rally wheels are also a direct bolt-on. Other suspension upgrades are possible with abundant aftermarket choices or stock high-performance components from the GN, SS, 442, or 2+2. A 7.5-inch GM 10-bolt was standard, so you can install a Posi unit from any similar-vintage S-series GM pickup truck or swap the whole rear from a 442 or SS. The 8.5-inch rear assembly in the '86-'87 (at least) Grand National and T-Type Buick is a nicer upgrade.
Cool Factor: B These GPs contain miles of style and an upscale look that was lacking in competing A-special and G-bodies of the era.form
Just to add to the previous post. The gears and posi can be taken from any 7.5 rear end. 78 & up G-body, 82 & up Camaro, Astro Van, S10. I built a 78 Malibu a few years back with the posi from a Turbo Buick and the 3:73 gears from a Astro. The motor was a 69 300 hp 350 with a 4 speed and I had no trouble with the rear end. I wouldn't drag race with it but it should hold up to normal abuse.
I believe there is a couple of years of engines from the Firebirds, maybe 77 and up, that don't have the correct mounting holes for your application. Otherwise I think pretty much all Pontiac V8's back to the 60's will fit.
__________________
1966 Strato Chief 2 door, 427 4 speed, 45,000 original miles
1966 Grande Parisienne, 396 1 of 23 factory air cars
Found a 400 cu in, bored out to 410, now it needs to fit in my GP. Any advice? What changes are required? Motor out of 70/71 Pontiac and has already been rebuilt from what I'm told.Any suggestions would be appreciated. By the way, a friend of mine gave me a set of Rally II wheels from a mid 70's Pontiac, I had them sandblasted and zinc coated. Then I laid down a few coats of silver and black paint on them. Can't wait to mount them on my GP. Found another set yesterday from an 84 Bonneville - will be restoring same
Re-reading my post from above this is supposed to be a bolt in swap. I think it comes down to a visual check of both engines mounting locations and the brackets that you have and determining whether they fit. You could also ask about this on another forum:
This is a US Pontiac site and I know plenty of individuals have already done this, there is a posting area for your type of car too.
The rally wheels sound good but I would just caution you to make sure the pairs are compatible in terms of diameter, offset and bolt pattern. The 84 Bonnevilles will no doubt be fine but those early ones might not. That same forum has plenty of information on rally wheel coding and compatibility as well.
THANKS FOR INFO, THE WHEELS I RECENTLY RESTORED CAME FROM AN 84 BONNEVILLE BUT WERE NOT THE CARS ORIGINAL WHEELS, THEY WERE SUPPOSED TO BE FROM MID TO LATE 70'S PONTIAC - THEY BOLTED UP FINE. I WILL BE CHECKING THEM ON MY CAR LATER NEXT WEEK.
I just purchased a 1980 GP identical to yours.I also purchase the Tach that will go in the car.I was wondering if you put yours in yet an what i need to make this work.
I just purchased a 1980 GP identical to yours.I also purchase the Tach that will go in the car.I was wondering if you put yours in yet an what i need to make this work.
Thanks David
Ditto on the welcome. I think I can help you as I have upgraded my cluster in my LeMans a few times over the years as I find the parts. Right now I have what appears to be a stock looking 73-77 Rally Cluster with one exception, it has a Trans Am 160 MPH speedo. I attach a photo.
GM tachs of this vintage and yours is really a 1978 first year introduction generally use their own two wire harness. If you put up a photo it woud help, front and back. One wire will be power and the other goes to the engine where on the distributor you should see connections labeled batt , tach. Use tach.
As for the cluster body usually the clock or blank face bodies are slightly different but I would need a photo of your parts to know for sure. Sometimes there are screws that have parts of the housing attached that lift off, sometimes the unit has mounts that screw in. Sometimes you will need a dremel tool to cut out metal to get yout part to fit.
Illumination is from the main cluster body wired through the main harness.
I just purchased a 1980 GP identical to yours.I also purchase the Tach that will go in the car.I was wondering if you put yours in yet an what i need to make this work.
Thanks David
I am not sure about the GP dash but I know there is an inline filter that was used on the same era Malibu. If it is necessary and not used the tach needle will jump around. You may want to verify if it is needed or not. Good luck. The dash looks awesome.
I have a neat 80 Grand Prix LJ with 4.9L, purchased last July and has been in storage since. Very good shape as it is from Alberta with only 76000Km on it. My question, what is the best way to get more power from this 301 - keeping it stock? These cars were always a bit lazy on takeoff. I had an 80GP over 20 years ago but totalled it in a moose collision, peeled the roof off her - vowed if I ever see another in good shape I'd have her
