13:1 Compression Pistons in 340 Small Block

Small combustion chambers only work better as far as quench which the intent is primarily to run pump gas without detonation.
Some designs of small chambers inhibit the breathing of the head.
  • Flat top Pistons on a modern build are really only possible on a stroker build because of the increased swept area, otherwise it would be very hard to get any kind of decent compression.
Each type build has its pro and cons. It depends on the intended goals of the build and operating costs of the fuel.

Depends on what you call decent, my 340 ran a flat top with a 55cc chamber aluminum head. It was 11.4-1 and ran on pump 93. With the same heads and a 21cc dish my 408 was 10.8-1.