Right Carb for my 340

I agree with Adam on the cam with use on a 3.73 gear.

With a 3.23 gear, I'd look at a 216 intake (2* ethier way) and a 228 exhaust (2* ethier way, but same way on both sides.) duration cam and a 600 cfm carb.

For mileage and OK power, with the M-1 dual plane intake, I'd use the smaller cam and carb.