Another underpowered 307 and badly geared gbody

[MrSony]

Especially when you punch it at 70 mph!😏

I think I redline about 115 or 120. Calculator says 5280rpm at 120, so more or less. 70mph is 3k... 70 is 2000 with the 200r4s .67 OD. 120 is only 3550... 😛

 

[kustomkyle]

Make a test pipe and remove the catalytic converter.

Play with the timing, advance it a couple degrees. "Test" the car. Make it run as good as it can with what you have.

 

[Texas82GP]

A gear swap is the easiest way to give it some guts. As stated above, you can get a limited slip differential that will fit the 7.5 housing out of a late model S10 or 4th gen Camaro. Being that your car is an 87, my guess is it has overdrive. If so, you are safe going with a 3.73. Monte SS's came with 3.73 and overdrive from the factory. If you don't have overdrive, then I'd be more conservative like 3.08, if you plan to use the car on the highway. If you go with the used 7.5 carrier out of a late model S10 or 4th Gen Camaro, they will be 28 spline. Your stock axles will be 26 spline. Order a set of axles for a Grand National on Summit....
https://www.summitracing.com/parts/msr-a102810/year/1987/make/buick/model/regal

Good advice on the exhaust given above. The converter, if it is original could easily be plugged. The Thornton manifolds or long tube headers recommended above together with a dual exhaust would really help the car breath. Beyond that, a good tune up and an effort to make sure everything else is functioning as designed are the low hanging fruit to make the car feel better. If you are leaking vacuum or have a burnt plug wire, its not going to run well.

 

[oldolds]

i have a 1980 olds cutlass Calais with a 307 out of an 85 cutlass wagon with about a thousand miles on the engine but it has been sitting for a few years and has some electrical problems. but it was free and the t tops are worth a few bucks. how do i find out what transmission and diff i got?

 

[TURNA]

Look at the trans pan.