Hi everyone. Ok hear is my situation I bought a 89 pontiac t/a a few days ago. The car originally had the 305 tpi engine. I have the 700r4 tranny that was recently rebuilt. The rpm gauge only goes up to 6000rpm. The previous owner bought a brand new gm goodwrench 350 motor and had it installed. So now it has the 350 tpi motor in it. I assume its the same as a l98 engine. I have have heard that some 305s had the "peanut" cam in them. Those cars would shift at 4500rpms at full throttle right? I assume thats why i have the wimpy rpm gauge in my car. Here is my wuestion when i floor the car and im going at full throttle it shifts at only 3800rpms in drive. It has a B@M shifter in it so i can shift into 1st and rap it up to 5000rpms and then shift into 2nd. Pushing it to 5000rpms seems to be pushing it. Now correct me if im wrong but with the 350 engines didnt they redline at 5500rpms? When im going at full throttle shouldnt it be shifting at around 5500rpms? I was told by the previous owner that there is a screw you can adjust by the intake manifold to make the tranny shift higher. If so what should i adjust it at? Thanks i hope some people can help me out.

 

This isnt a transmission problem but what the hey.

The TPI design sucks "I wouldnt change it if I had it though".
The engine cant get engough air through the throttle body to feed the engine and aftermarket parts are out of this world, thats why people complain about TPI. If your shifting around 5k thats about where the GM crate engine hits the wall 5k-5500k thats just the way GM made them. The 305's your talking about were dogs "stock" but they still shifted higher then 4500 they just dident make any power past 4500 so there's no point in pushing them.

 

Thanks for the info i really apprciate it!

 

Shifting your motor at 5,000 rpm should be just fine, I would probably shift it at 5,500 because that is when I got the best times out of my stock motor...the goodwrench motor can handle 5,500 easy enough. As far as the trans shifting out of gear at 3,800 rpm at full throttle, there is a cable running to the throttle body on the driversside that has a black square button that you can push in and pull/push the cable. If you pull the cable to the rear of the car, the trans will shift at a higher rpm, pushing it towards the car will make it shift sooner. I would try messing with it until you find a spot that you like, don't push or pull it more than a quarter of an inch at a time, it doesn't take much. Hope this helps.

 

Thanks 89z28 that helps me out alot! I really appreciate it.