HI all,

I have a 1988 454 Gen IV block with the high perf merc Cast Iron stock heads. They have a large crack now that can't be reliablable repaired. My Question is this. Can I use a pair of Stock 2000 502 Gen VI heads with my Mark IV 454 Block?? Any suggestions would be greatly appreciated. I was unable to find another set of the Mark IV heads.

Dave

I am not absolutely sure, but I think the stock gen 6 heads are incompatible with the mark 4 block due to different cooling passages. You may want to take a look at the aluminum edelbrock heads (marine) that summit has listed for this application. They have inconnel exhuast valves and severe duty intakes and are reasonably priced at $734 each ready to run. Aluminum has several advantages over the cast in my opinion.

BT

won't work on gen IV. Good head though especially with bigger valves installed. Pick up an old '96 from a HD truck and get the roller cam too.

I just saw a set of gen 6 on ebay that claim to be "service block" which they say means it will fit any yr because it has extra material? Do a search for "bbc heads" and look for a buy it now of around 650,I think. Comes with a hyd non roller cam that will run an old style mech fuel pump,didn't give the specs.Good luck.

I think they will work. ya have to drill a water passage hole in the block. In the felpro catalog it show ya how.i am not 100% sure on the gen 6.


just but some merlin heads new or look in the parts section here i have even seen some used merlin for sale .Buy the time you do the machine work rebuilding the used one it want be much more for the new

will not work. there is a rumor, that a certain head gasket will stop the water leaks into the oil pan. it is a myth. i have tried it.

GM high performance has the heads available for MK IV brand new