I am still conducting research, but it looks like the 3800 SC provide the best HP, is reliable and will fit the J body. Yes, I know, engine mounts, wiring, computer, relocation of components etc. but I'm told it will fit. The question I have is whether the 5 spd manual can handle the 240+ HP or should I be shopping for trany parts or a new trany? I will very likely be changing the shafts and front and rear hubs etc. to be able to have 4-wheel discâ€™s to improve braking.
The 5-speed will take the 3800 S/C fine, no problems. The only real problem is the flywheel, you would need a special flywheel.
On an auto, the 4T65E which comes with the 3800 S/C damn nearly weighs as much as the engine and it huge (not as big as the 4T80E, though). I've never seen anyone put the 3800 in a Cavalier and used the Auto with it.
the transmission is up to the task of taking the abuse.
thats the same transmission that the fiero guys use behind LT1 LS1, regular 350v8's. 3800 S.C and anything else they can chuck at it.
it holds fine.
just get a Fbody 3800 Flywheel and get it machined down to the same thickness as the 3.1L one.
Thanks everyone for the recommendations. I love manual transmissions rather than the auto, so I think I will stick with what I have. Not sure if there is a benefit to going with an aluminium fly-wheel rather than machining down the steel 3800, apart from weight.
As for the question that Jakeroonie asked, it is listed in the title but I will answer anyway. The engine is a 3800 Series II SC.