upon my travels looking for the mystical DOHC 6g74 Mivec engine i came across this thread from some time ago:

http://www.magnaclub.org/forums/printthread.php?t=11709&page=3&pp=10

discussing the 6g72 mivec i was wondering if anything ever eventuated from that discussion and if anybody knows if the 6g74 dohc mivec head will fit the sohc version.

dont think that it is a certain that it can be done as it never has,

only way i geuss u will know if u take the engines apart and try it, other wise speak to dave from rpw

I've been told the SOHC 6G74 heads will fit a SOHC 6G72 ok, so it's possible the same holds true for the DOHC versions.