2.5 phase 2 heads on 2.5 phase 1 block

[logic23]

Has anyone tried this? putting 2000 phase 2 heads on 98 phase 1 block? Thanks

[mellow65]

you would have some crazy high compression, if i remember right the phase one pistons come past the deck of the block just barely, but more then the phase 2 does. so the CCs in the combustion chamber is smaller in the phase 2 heads.

 

it's doable, but still the question is why, the DOHC heads aren't bad.

 

not unless it's the thing of "I have all these parts laying around lets see if I can make an engine"

[mdjdc]

It is an option. You should use the DOHC head gaskets to minimize any interference issues. I have a friend who is a subie mechanic and he has done it for one of his engines because he had the parts lying around and didn't want to buy another engine.

 

Good Luck

[RallyKeith]

I know it works the other way around. If you go to the dealer and buy a new short block for a Phase 1 you get the same thing as used for the Phase 2.

[logic23]

Yeah I have three good phase 1 2.5 lower ends and 2 good sets of heads off a phase 2 2.5. The pistons have the deep square recess so i think the compression ratio should work.