well i picked up a crane cam and was told that if i put it in the 305 i have that it would cause the valve to touch the piston.... it is a 465/488 lift.. 114 deg cam..... he said because its a 305 with a smaller bore(witch we know) that it would open the valves to much.....is he full of u know what ,or is there any truth to this...i dont think the cam is that big...