Says they are 60 cc chamber heads which I would assume they are close chambers...and the heads fit all small blocks 67 to 91 318,340 and 360. Specs show a Fel Pro head gasket 1008.
So a 68 to 71 340 is going to be a bolt on with those heads and head gaskets.....
Nope, and a .650" lift roller cam advertised to fit those engines in those years won't work without modification either. How many people would really intend to bolt them on to a stock bottom end 340 with a positive deck piston?