What motor would you choose? To put in a Z car.

[Kracka]

I sure wouldn't want to add 100 lbs to the front end of a car that wasn't needed as it will have a significant impact on steering feel and handling. Are you building this car for straight line performance, to dominate the twisties, or a combo of both? If the answer is a combo of both then its tough to argue with a forced induction 4-cylinder since they are lighter in weight but still make the power.