Dont ruin the car by putting a V8 in it. That just destroys the car. I have a 1989 Porsche 944 Turbo. I decided to not get the Turbo S because im planing on modifing everything that makes the Turbo S better than the standard Turbo.
The 1986-83 944's have a strang bolt patter so stay away from them if you want to put nicer wheels on it. Get a 1987- newer 944.
And they are fast in the quarter. A 400RWHP 944 runs in the 10's. And it is relitivly easy to get that kind of horsepower out of the 944 turbo.
This is not just another sports car tho. it is a porsche and requies the same matinence that any other porsche requires. Regular prteventitive matinence. Parts arent cheap and it can be a pain sometimes. DOnt expect it to be very reliable if you dont put money into the car.
Good luck