Felpro makes gaskets to bolt mark4 heads on a gen5 block. I think 17046 is the number maybe 17048 too BBB

Also these motors are mentioned as two bolt blocks, gen5 and newer only come in 4 bolt . They have to be mark4. Use felpro 17040 head gaskets. Am I post hoggin' ?

Yeah bbb,quit hoggin the board!!! get over to the brezze your buddy tripps

Big Block Billy,

Thanks for the info. I dont think your hoggin, I really need the help...

So everyone agrees that the Vortec heads will work on the older block with the special Fel-Pro gasket?

The Merlin heads will also work on MKIV and GENV engines.
The FelPro 17048 head gasket is for a bore size of 4.500, I believe the 17040 is for a bore of up top 4.350, 4.310 for sure.

Check into this carefully. I was told that my GM Mark 4 heads would not work properly on a Gen 5 or 6 block no matter what gasket. Im not sure about the other way around. Aftermarket heads on the other hand will fit any of them. I think.

I picked up a complete 454 today from the salvage. they did not gaurantee the lower end but did gaurantee the heads rebuildable. supposedly had a rod knock. the heads were 049 castings. $100 we just had to dig it out of their motor pile inside an old barn. Just drpped it at the machine shop to be checked out...