GRAND PRIX 78 Grand Prix Restoration

Jun 16, 2015
4
1
New York NY.
I'm looking for a shop with experience restoring g-body pontiacs.. I have a 78 GP, with PS, PW, Floor console Automatic shift. Very good good shape, no rust, looking for engine/ auto transmission.
 

buick7332

Master Mechanic
Oct 21, 2014
263
63
N.E. Philadelphia area
I'm looking for a shop with experience restoring g-body pontiacs.. I have a 78 GP, with PS, PW, Floor console Automatic shift. Very good good shape, no rust, looking for engine/ auto transmission.
If your car has a 301 motor keep your motor mounts! They are the ONLY ones that will work with a bigger Pontiac motor. Also, G-body 301 mounts are almost extinct.
 

John Harrington

n00b
Thread starter
Jun 16, 2015
4
1
New York NY.
Thank you for the advice, I believe it is a 301 motor, if that's the same as a 4.9 Litre V8 or 301.6 cu. Which is what is has, the small V8. I wanted to do an LS upgrade with a new overdrive trans, but I'm not sure what to do..
 

pontiac guy

G-Body Guru
Oct 28, 2016
550
93
Royse City, TX
Assuming you like the automatic. Keep the 301. Use a 2004R trans. Add the extensions for the cross member. Lose the lock up feature. It's nice but it's not going to add much to the car but complexity. Find a Auburn 3 series carrier and put a 3.23 or 3.42 in the rear. Go to a nice 15 inch wheel. Add tires. If they're tall use the 3.42. Keep your factory auto shifter. It's a factory ratchet shifter. If you set it right it will not go down to first but it will do PRND32. Go dual exhaust off the manifolds. Advance the static timing 1-2 degrees. Go 1 cooler on the plug. Gap them at .045. Good tune up. Don't bother with Accel or similar. Just use quality parts. Adjust your secondary air valve to open sooner. Replace all the bushings in the suspension and new springs all around. Do the steering parts and get an alignment.

This is the cheapest place to start and will give you a super nice driver. From here you can determine if you are happy. None of the parts you put in are wasted if you go with more motor.
Message me if you have specific questions. I love driving my 301 daily and it gets me good mileage to boot.
 
  • Useful
  • Like
  • Winner
Reactions: 2 users

Texas82GP

Just-a-worm
Supporting Member
Apr 3, 2015
7,040
113
Spring, Texas
Assuming you like the automatic. Keep the 301. Use a 2004R trans. Add the extensions for the cross member. Lose the lock up feature. It's nice but it's not going to add much to the car but complexity. Find a Auburn 3 series carrier and put a 3.23 or 3.42 in the rear. Go to a nice 15 inch wheel. Add tires. If they're tall use the 3.42. Keep your factory auto shifter. It's a factory ratchet shifter. If you set it right it will not go down to first but it will do PRND32. Go dual exhaust off the manifolds. Advance the static timing 1-2 degrees. Go 1 cooler on the plug. Gap them at .045. Good tune up. Don't bother with Accel or similar. Just use quality parts. Adjust your secondary air valve to open sooner. Replace all the bushings in the suspension and new springs all around. Do the steering parts and get an alignment.

This is the cheapest place to start and will give you a super nice driver. From here you can determine if you are happy. None of the parts you put in are wasted if you go with more motor.
Message me if you have specific questions. I love driving my 301 daily and it gets me good mileage to boot.
I think this is all great advice.
 
  • Agree
Reactions: 1 user

pagrunt

Geezer
Sep 14, 2014
6,776
113
Elderton, Pa
To add to that dump the '78 only front spindles & specific steering/brake parts & go with either '79 up or about '98 up 2wd Blazer spindles.
 
  • Like
Reactions: 1 user
G-Body Performance Upgrades

GBodyForum is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com. Amazon, the Amazon logo, AmazonSupply, and the AmazonSupply logo are trademarks of Amazon.com, Inc. or its affiliates.

Please support GBodyForum Sponsors

Classic Truck ConsolesDixie Restoration DepotMike's MontesP-S-TSouthside Machine PerformanceUMI Performance

ContactAdmin@GBodyForum.comfor info on becoming a sponsor