Well i was wondering if the Summit Racing 383 engine rebuild kit would fit on my 1986 camaro. Cause it says ending year 1985 but im not sure.

part number would help

1986 was the introduction of the 1 piece rear main seal. An earlier crankshaft won't fit without an expensive adapter.

CSUM383KIT and my car has a 305 in it

Yep

And Summit still carries lots of kits that will work for an 86. Check out their website and search their Eagle rotating assemblies. You can still get the Hypereutectic Pistons, cast crank, at the ratings and price you're looking at in the other mentioned kit.

You can't make a 383 out of a 305.