So I'm having my block bored .030 over and I wanna run a procharger, what's the best piston to use in this case as far as compression?? I have the 5.0 btw.
Ross/ Diamond / Manley are all great! Honestly I wouldn't spend a bunch of money on them though. Since it looks like you are a 5.0 pushrod engine and I'm assuming the stock block which is only good for ~500-550 anyway
I am no expert but if I were running the same set up I would use Probe SRS Forged Pistons 10682-030. They are a little pricey but still a good choice. I think the compression should be around 9.0-9.25 with stock to moderately worked GT40P's.
I am currently running a similar cast piston with the same compression distance and head volume on my 306 with ported GT40P's and really like the combination. If you think the compression might still be a bit high for a blower application you can drop down to about 1575 on the compression distance with the same style flat top piston.