I want to bump up to ~ 9.5:1 - 10.0:1 compression (whatever I can run safely on pump gas - we have 94 octane around at some gas stations still) on my 72 Supreme 350 4bbl. Will also be running a TH350 and 3.42's. No other mods to stock 7A heads.

Which pistons would work best? Speed Pro ZWL2320F.. or are they too high?

 

I'm assuming your cam will be stock too? If so, shoot for 9.5, not 10.0:1. I think that pistons is the L2321. Does it need to be bored or are you going to just hone it?

 

It also depends how far the pistons are down the hole. Usually they end up about .025" below deck and the 2320 piston will be OK, especially with a thick head gasket, like the Corteco 55660 or Fel Pro.

 

Will be honed. I won't be using a stock cam though... just a bit higher than the ones used in 1970 is what I would like. Not crazy W31 but close, as I still want to use my A/C.

 

Then yes go with the higher comp pistons, and I have the perfect cam recommendation for that combo, an Erson TQ40, 220/228 on a 110, .504 lift, strong midrange.

 

I don`t know which ones to get though to get around 9.5 - 10:1

 

It'll depend on deck height, head cc and gasket thickness.
I have the L2321, about .005 in the hole, .040 gasket thickness, about 66cc on the heads. Comes out to roughly 9.75:1.