Re: head transplant
According to JMM, the EF/EL head is the best for performance. If you plan on doing other mods, this may be the go. If not...steer clear of anything EA/EB- they have some design issues (note frequend EA/EB head gasget/cracked head discussions)
AU have smaller valve areas or something...EB2/ED doesn't really get mentioned anywhere, but are probably considerably cheaper than EF/EL/AU. (note that any EL after january 1998 could be "Hybrid EL/AU" engine with the AU head...)
I'm sure someone has some facts to prove this babble...or disprove it...either way we both learn something...
1987 Jaguar Sovereign - Metallic Green
3.6L DOHC 24 Valve