the y8 has timing of 12* so if i put a z6 head on it would it have 16* and would it run ok? reason i want to do this i couldnt tune my y8 and that car got tottaled but now i have a 90 civic and want to do an engine swap and turbo it.

 

If you run a programmable ECU (Uberdata, Crome, Hondata)you can make necessary timing adjustments there regardless of the type of head you're running.

Oh and also the compression ratio will be dramtically affected/lowered by swapping on a Z6 head because the combustion chambers on the Z6 head are larger than the Y8 ones.