Will a 1968 gm Chevy block fit to 1992 Camaro rs and only change 350heads?

No, a 1968 Chevy small-block will not simply bolt into a 1992 Camaro RS and only require head changes. While both are small-blocks, there are significant differences that prevent a direct swap:

* Motor Mounts: The engine mounts on a 1968 engine and a 1992 Camaro are completely different. You'd need new motor mounts and potentially fabrication to make it fit.

* Bellhousing: The bellhousing pattern (where the transmission bolts to the engine) changed between the generations. You'll need a bellhousing appropriate for the 1992 Camaro's transmission.

* Oil Pan: The oil pan will likely not fit the 1992 Camaro's subframe. A new oil pan will be needed.

* Accessories: The alternator, power steering pump, and other accessories are likely in different locations and use different brackets. You'll need to adapt or replace these.

* Exhaust Manifolds/Headers: The exhaust system will need to be completely changed.

Simply changing the heads won't address these fundamental incompatibilities. While a 1968 small-block *could* be installed, it's a major project requiring significant modifications and fabrication beyond just swapping heads. It's not a simple bolt-in swap.