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i see your point about $$$ vs gain there, but it may still be a possibility, and that's all i'm saying!
cheers.
cheers.
but we're not talking about a UZ V8 vs a 6 pot head - we're talking a GZ V12 head and 2x 6 pot heads.
the 7AFE is a 4 cylinder and the 4AGE is a 4 cylinder from two totally different families of engine (even the bock heights are different) - yet the only thing needed to make the two come together is a 4AGE timing belt and crank pulley with 2mm machined off the idler pulley to let the belt fit.
why can we not look at fitting any JZ series 6cyl head to the V12 GZ? no doubt in my mind you will need a custom length belt made up to drive the cams along with a custom inlet manifold - but that may be a small price to pay for someone who can only source a block.
if someone can post up a photo of a GZ head gasket and a JZ series head (both 1JZ and 2JZ) then we will be able to determine for sure.
Cylinder bore size and compression effects are the one of the biggest problems with using a 1JZ or a 1G head.
The 1G has a 75MM bore chances are, using this head on the 81MM bore 1GZ will cause a drastic increase in compression not to mention, I hightly doubt that the bore spacing is even close.
The 1JZ has a 86MM bore and chance are, using this head on the 81MM 1GZ bore wil cause a drastic drop in compression which could be good for forced induction, but using this setup will also cause a substaintial lose of quench area which will increase the likely hood of detonation and will lower performance possibility. This again is barring whether or not the bore spacing is the same which again, I hightly doubt, especially cause toyota usually attempts to have pretty thick walls between cylinders on thier turbo engines and the JZ and its 86mm bore and intended as to have a turbo will most likely be longer...
One thing Im surprised that was not mentioned with the 1jz or 1g swap possibilities is a 7M head. Out of all the I6 Toyota engines, this would be the closest one with the 7M engine having an 83mm bore so the spacing might be a lot closer (or possibly the same)... These heads are readily avalible and cheap (at least here in the states) but I still dont see this being a swap worth the effort or cost.