Will a 1993 Geo Prizm engine fit in a 1991 Geo Prizm?

Answer 1

The problem you will encounter is . . . if you want your emissions, etc. to work you will have to change intake manifolds. However, this would be impossible to put your 93 intake onto your 91 head ( the ports will not line up). Can you just put the 91 head on the 93 engine? No, on the 91's the valve-relief is all in the pistons whereas on the 93 it's all in the head (with very slight dimples in the pistons) so if you bolt the 91 head on the 93 block, there will be no room for the valves to open (plus, on 93 - 97 motors the cam has approx a 1.65 in. lift and on the 91 motor it's approx 1.35 in. so there would definitely be no room). To actually make this work, you would also have to change the pistons in your 93 motor to 91 pistons.