Yes.... same basic piston setup on a 340 and we have 10:1. Pistons measured at.004-.005" out of the hole. Cranking compression at 156-161 at 2400' elevation with a 212 @ 050" cam (intake). OP, if you would check the cranking compressions on all cylinders, that would help verify this.
The one question I have on the info leading to compression is if the pistons are really level with the deck as claimed..... Typical Icon pistons height sit about .010-.012" below nominal LA deck height.... lowers static CR by a couple of tenths. And with high deck height and a thick head gasket, SCR could be down close to 9.5..... but that is not going to be holding back the engine all that much at the top end.
IMHO, still not a good description from the OP as to what seems to be 'weak'. Boggy on the street or what? My son's 340 is very similar for heads, CR, and intake, with smaller cam, almost .100" less lift, Spitfire headers, and 600 cfm carb, 3.55 rear and 220 RPM stall TC on a 904 auto.... not the least bit boggy..... traction is the problem. Will spin tires at just over half throttle from a stop.