Yes- let me know what gasket I need. For $500 for brand new heads I'd be a fool not to. I've read in some posts that you need to scribe the outline of the lifter valley so you can see how close the water jacket is. Is this so? If so, at what point is not enough overlap?

http://www.chevelles.com/forums/showthread.php?t=316022

Use a quality gasket correct to your block. Careful to check water passages near lifter valley. This is where you would get leakage.

so let me get this straight, you can use the 088 genvi heads, on a geniv block with the right gaskets, is that right Haxby speed....

Yes, and depending on which Mark IV block you've got it's also a good time to convert it to parallel flow vs. series.

Haxby-
I picked up the heads today, what gasket do I need. From what I can tell my block has the three holes that are needed.

What's your bore size?

It's 4.25. Here is a picture of the deck as well... Yes, it's being resurfaced, dropped the block off at the Machine shop this morning when I picked up the heads.

Felpro 17042 will work fine and will give you parallel flow which the block is already set up for.

Perfect and thanks for your help!

No problem, the spot that has the most trouble is the upper hole between 5 and 7. You can lay the head on the block with no gasket and mark the edge with a sharpie to make sure you're gonna have enough squish there before you put it all together. Never hurts to double check everything.