will a 1991 k1500 chevy 5.7 engine be compatible in 1998 chevy k1500 that had 5.7

A vortec and throttle body have diferent degree heads.intake off vortec will not bolt tohead ofthrottle body engine.

you have to swap the heads and intake manifold from ur old motor and put it on ur new motor i was wondering the same thing expect a 91 to a vortec an saw that i would just have to swap the heads an intake manifold to the new motor

Can I change out on a 1996 gmc 350 fuel injected in put it in a 1991 chev 1500 or what will I have to do the 91 was a350 also but not a fuel injected