2000 Mitsubishi Galant
2.4 16v 4g64 176,000 miles

Was out of town and timing went out, I was able to drive back home about 60 miles before the timing belt finally broke. Since this engine was an interference engine I'm assuming I bent valves. I plan on replacing the obvious, timing belt and valves but what else may have been damaged that I will need to check. Should I rebuild the entire head since I have it off already or just worry about replacing damaged parts? Thanks.

 

Probably a bit late and I've never owned one of these, but worked on and rebuilt several engines.

As far as valves go just replace the damaged ones and check the valve guides and seats for damage.
Take all of the valves out and do a roll test on the end of a flat bench. Bent ones are usually obvious.
Rub down any small dents on the piston crown, so carbon build up and hot spotting is less likely. Small dents won't be an issue.

It's up to you but I usually replace the valve stem oil seals while the valves are out.
Just make sure all valves lap in and seal nicely and go back in their original guides (where applicable)

Oil everything up with assembly lube or a thick oil during assembly, you don't want a dry start.

Obviously replace consumables like belts and seals. Tensioner is advisable too.

Hope that helps a bit.