Hi guys i read the info given before i wrote but still dont quite know, i have an ea and an eb engine and want to make one out of both, what combination is better, ea block with eb head or eb block with ea head, and will an el computer go into either of these combos, its a manual too so i gathering i will need a manual computer if they will fit????

Okay you can build a motor out of an EA and EB but the compressions won't be standard, the EL computer will run it with all the right looms and manifolds etc, I havn't personally havn't done anything like this, but it will work if you reserch and look at otherpeoples builds.

So an EA head on EB block (assume both is 3.9) = same same
EA onto EBII (4L) it will raise compression = ratio i have no idea
EBII onto EA will lower compression = ratio I have no idea

thanks heaps for that, and yes it is a s2 eb, so is raising the compression better than lowering, au head gasket better than the original ones too i keep hearing is this true

AU head gasket = win.

the higher compression is good in an N/A application.

lower compression is better for boost

sweet thanks haeps for the info, should go well as the ea has a cam. it has run 15.3 down the quarter but it has a horrible grinding noise only at low rpm but shouldnt be a problem now with the eb bottom end.