mercruiser bought the head from GM. they didnt make the head for the 3.0
however please help us help you
there are 3 head designs. the really early 1974 and older. the 1975 to 1990 and the 1991 and later.
you need to keep the 1990 and older head with the 1990 and older block
you need to keep the 1991 and later head with the 1991 and later block
mixing and matching can be done, however you are on your own.
what motor do you have?
what head did you buy?
HEllo;
Ok, so corrected on Gm part being made by Gm.
1988 3.0. However, through Mercruiser help. with the serial number that I have, indicates the engine is from 70's sometime. I bought 8m0115134. We discussed cutting down the rocker stud towers as the height difference is the dimension of the hex on the screw in stud. That is a possibility. I will have to pull the head off to see if the rocker tower is tapered inside so as to not allow cut down and extending threads.
What research I did earlier, and verified today, Ford truck 240/300 cu in pushrods may work as well. I am concerned, without the lifters pumped up, the pushrod may drag on the side of the head. I may be able to rout out the pushrod channel to make room. I can't figure out, without running the engine to pump up the lifters, if that is so. I am not anxious to run the engine and risk damage to the whole valve train. (I would have to make a stand to run the engine anyway, as the hull is gutted and being restored too.)
This just in, another supplier indicated some of these heads were not machined properly. "Get your dealer to warrantee it" Is this why Mercury is telling me to cut down the rocker towers?
Any Ideas and input appreciated.
