cylinder head

Will a 1981 kz 650 H cylinder head fit a 1982 kz 750 H motor. I know the gaskets are the same but not sure on the head. Are there any huge differences between them.

I'm not sure on the actual specifics, but I'd be willing to bet that the 650 cams are going to have diff specs (lift and duration) on the lobes, and the cam chain guides might also be diff in dimensions and where/how they mount.

I'm curious, especially since most folks I've seen have gone UP in CC's when swapping engine parts, but why does the cylinder head on your bike need to be replaced?

I have the head off and am going to lap the valves with my dad. The reason I was looking at another head is because 2 of the spark plug holes have helicoils in them and the tach gear assembly is rounded off so that I can not remove and replace the worm gear. The bike does not have many miles on it but the previous owner was a little hard on her. I doing the valves because they have some build up on them from sitting for 10 years with vanished gas.

If the 81 KZ650H has a HyVo cam chain then it's a bolt on, it will give you a little higher compression and smaller valves.

thanks for info steell.