Building 340 short block

The KB cast pistons will work fine it you are not going to use nitrous, turbo, or supercharger. Just make sure the ring gap is set to KB specs. You using "Edelbrock 360" or the "340" heads? Best set up would be the 360 closed chamber heads with pistons set to zero deck. If you don't have the heads already go with the closed chamber 360 Edelbrock heads so you can build a quench combustion chamber.