85 Suburban engine help

[BigBlockBurby]

So my 85 suburban needs a new long block, the motor it came with is an old 70's era block and heads that have been beat to hell, the guy ran it with open breathers on the valve cover and no air cleaner. It leaks oil and either way she has to come out, the wrong motor mounts are on there and its causing my engine and trans/tc to tip. My issue is, I have a rebuilt short block in my garage, from an 89 chevy pick up, TBI 350. The bottom end was rebuilt, but the heads were never done. Motor had developed a rod knock, so i pulled the motor. Blah blah blah, anywho, I have a set of 462624 heads with a fresh rebuilt, was going to use them on my suburban when I thought the top end was just the issue. Im curious, will my 462624 heads bolt up to my 89 roller block? Im trying to retain everything on the suburban (changing intake and probably carb once I get all together) any issues I'd have to deal with? Any tips for me, I just dont want to throw it all together unless Im absolutely sure the short block and heads will go together and make the truck run good you know. Any advice would be appreciated!