Rebuild 63 camper Engine ( first Timer)

[BarnShooter]

My O code 1500 Engine was not turning over all the way so I tore it completely down. Turns out a piston blew up and tore the jug up along the way. I have purchased a 1600 DP to put back into the bus since I would like more HP. SO id like to put this 1500 engine back together stock unless I can upgrade some other parts to gain more HP without sacrificing too much extra cash.

So heres the questions:
1. reliable website or company best for buying engine parts suggestions?
2. What kind of kit would get me the most bang for my buck?
3.Do I need new heads, valves, rockers, and lifters? or can I just re use the old ones?
4. there are teeth missing off of the cam, I think the crank is ok, but should I get it checked ?
5. Forged or cast Iron Piston sets?
6. How do I know what mm Piston set I need? 85.5? 87?

You all are very knowledgeable and I appreciate the input.

[jjohnson67]

1500 pistons? Are you sure or are you going by the engine id? Kinda difficult to find. Cut for 1600 is my best recommendations. Would have to cut heads too. Crank worn? Wire wheel between valves and spark plugs... Cracks=junk.