Engine top end slab side -87

[Fkpn]

Hi, I have bought a slabside -87 with top end from a 91-92 with shims. The issue is that I have a metal sound that follow the rpm, it doesn’t sound when the engine is at low idle speed. The sound is like somithing hit something. I can’t see any damage when I remove the valve cover.

is this replace with a newer top end possible at the 1052 engine? Do I need to replace anything more with this modification?

[Upshotknothole]

Check the valve clearances and cam chain slack? These engines have pretty noisy top ends.