How to build a 13 second 340 Duster

Like what Ron said...compression is a combination of factors. Piston part number has a very small part of that. Flat tops can be 8:1 or less, or 11.5:1, depnding on the rest of the pakcage, and the guy setting it up. So, when I say "10:1 is what I like", I'm referring to real calculated static compression ratio. Pisotns you see that say "10.5:1 with 72cc heads" are not. They are whatever they end up at, when the block is decked, and with whatever the head chamber size ends up at after grinding or replacing valves and doing a vlave job and cleanup cut on the heads, and with whatever head gasket your builder uses. I've seen many small blocks with the old school TRW "10.5:1 stock replacement forged pistons" that calculate to 9:1 when the rest is taken into account thru measurement. Again, it comes back to a complete rebuild with an eye on making solid dependable performance, or a rebuild. I've priced a couple small blocks this week, and depending on what you start with, around me, the costs were around $4000-6500. Depending on cubic inch and options. None of these are less than 400hp tho.