I just replaced the heads on my 92 Chevy C1500 4.3 and in the process of reassembly, I found a gap between the intake manifold and the block. The gap is about the thickness of a nickel. Can I use “the right stuff” to plug the gap or is there something else I should do?

The heads bolted on with no problem and so did the intake manifold so I assume they are seated evenly. The replacement heads are from a salvage yard and had pressed in studs instead of screwed in studs, they also came with longer push rods but I kept the original shorter ones because I am assuming it was for a different cam or something. but otherwise they looked identical.

I noticed the gap after putting on new intake manifold gaskets and RTV… If I unbolt the intake manifold can I still use the same gaskets or do I have to buy a new pair?

Any thoughts appreciated. Thanks!