I am rebuiling a 3.4 for my bird. Does anyone know if you can put a 3.8 crankshaft in a 3.4?

 

Uh, no. Not even close... The 3.8L is a 90-degree V6, and the 3.4L is a 60-degree V6. Even if you could get it in the engine, none of the connecting rods would bolt on because of how the cranks are so different.

They don't even look close to being the same.

 

the connecting rods would bolt up fine, but they would be at the wrong angle, and the cylinders probably wouldn't work because of the pressure being put at the wrong point...

plus... the 3.8L has a different firing style than the 3.4/3.1/2.8. all of the 60* motors i just listed fire 1-2-3-4-5-6 and the 3.8 is like 2-4-3-1-5-6 or something wierd like a v8. its not sequential like the 60* so even if you could get the crank to work, the engine wouldnt fire right...