Tips on selecting Pistons??

I have rebuilt engines before but typically I would find a suitable kit and buy the kit for x- amount of dollars and then had everything to put it together.

The kits usually came with pistons and who knows what kind of compression they were running.

This engine build I would like to know what kind of compression it has and more specs than would be with a generic kit.

So any tips on calculating compression and what could or should go into the engine.

The engine in question:

360 with a build date of 7 /24/74 ....presumably for a 75 vehicle. This engine came out of an RV. The intake was missing so I have no idea if it is a 2 or 4 barrel version.

I live at almost 6k feet in altitude so the compression here is not what it would be at sea level.

The engine is intended for a street car....a pretty mean street car. Not really into the race thing. Will be running street tires with a 4 speed and undetermined gears.

ok, let the discussion begin :)