No way, not on a 340 with that camshaft. Ain't gonna have the legs to make that m1 work. An Ede Air Gap will mudhole the M1. BTDT, along with many others, got the t-shirt. :)
I agree here. your 340 will need the 4:10 rear gear and a 4000 + rpm stall converter along with better heads and ALLOT more cam before the M1 is needed. Even then the rpm might be a better choice for a street car.