I am putting a set of Vortec heads on a ZZ4 short block. When I set the heads on the block I can get one or the other dowel pin to seat properly the other will not, resulting in the head being up on the block a bit. ( see pictures ) A few light taps with a rubber mallet had the head will seat properly. Is this something to be concerned about? Also the block is slightly used and there is a trace of what looks like copper on the deck from the old gaskets. Could this prevent the new head gaskets from sealing properly?

 

I wouldn't be worried about it since all it takes to get it to set flat is a few light taps with a hammer.

 

Its fine. I had to do the same with my old 350 and the current 454 and haven't had any sealing problems.

 

I'd clean up that block deck surface better first, though.

 

Whats the best way to clean the deck surface

 

The best way to manually do it, in my experience, is to buy a box of razor blades and alot of brake cleaner. Use the razor blades to scrape/peel everything off the surface, and the brake cleaner to get the surface chemically clean. I've done it this way many times and never had a problem. Just have to be careful not to gouge the surface with the edge of the razor blade. You'll probably use 2 or 3 blades on each deck, because you want a sharp blade because they work better. Don't be chintsy lol.