I'm a pontiac guy from South Dakota and just snagged a real solid 1979 tenth anniversary trans am. She's an auto car and came with the 403 and I intend to keep her mostly original. I came to learn about your oldsmobile engines, particularly the 403, and what I can do to improve its performance and reliability. Already learned a lot by browsing. Thanks in advance!

 

Everyone enjoys pictures of cars >>> How To Post Pictures/Images. Welcome to the site.

 

Welcome

 

Welcome to the site!

One of the best performance improvements is better rear gears. From what I recall many of those TAs had 2.41 rear gears.

On my first car (1970 Cutlass Supreme) I swapped the original 2.56 gears for 3.08 and it felt like I added 50 horsepower. Then later I swaped the 3.08s to 3.55s and it felt like another horsepower increase. Those rear gear changes were the best performance modifications I ever did - even better than headers and a new camshaft.

 

This car has the 2.73 according to the build sheet, and a swap is definitely on the list. Thinking 3.23 or 3.42. Hoping to get a reliable 325 hp or so out of this 403, with peak power at or below 5500. Should be pretty straightforward I hope.

 

Sounds like a solid plan. Those 403s were rated at 185 horsepower but a whopping 320 ft-lbs torque at a relatively low RPM (2400 I think?) so don’t focus too much on horsepower - take advantage of the torque those things can make.

 

Yes sir. Not looking to get carried away, 325 Hp or so would be perfect, preferably peaking before 5500. I'd like to keep the under hood appearance fairly close to stock as well. The older I get the more I appreciate originality over performance in semi rare cars like this lol.

 

Welcome aboard, cool car !

Is she bone stock, exhaust, everything, etc ?

 

Its a project at this point, but the body is rock solid and wont require any panel replacement and minimal repair, which is a massive departure from the 72 lemans I am working on currently for my father. Interior will need complete replacement.