HELP, 64 Valiant motor mounts

You can probably use either type of biscuit mount. I had the later thin ones on my 1965 273 (for more hood clearance) until I had to switch to the later Federal p.s. pump which hit the K-frame, so went back to the original thick ones. With the thin ones, I had to **** them so one bump fit in a bracket hole and drilled another hole for the other bump. Might also consider what that does to your driveshaft angle.