Here is something i am going to get flames for...

[blight]

Ok i want to build a gm l4 turbo motor. for a fiero. Although i do not know which motor to choose from. which motor is is going to get me to 250hp the easiest? and what donar car should i get it out of?

[MagicRat]

Ah yes, the Chevrolet Fiero.......................

Seriously, forget the automotive 4 cyl blocks.
What you want is the marine block 3 liter engine.

It is externally identical to the 2.5 Iron Duke, but much stronger internally.
Stock it develops 140 hp and is designed to run at full throttle all day.
Modified, it shoudl tolerate 250 hp in an automotive application, and last longer than a modified Fiero 2.8 V6.

[Jaguar D-Type]

Actually, it is the Pontiac Fiero (1980s mid-engine sports car).