I Have a situation

You need a 750 carb, you need either 340 exhaust manifolds or headers. The 340's will fit in an early a body with less hassle than the d450's or tti's. Not sure what trans you are running but I would guess 4 speed with the 3:55s. Also go to the FBO website and read up on timing. You want as much inital advance as your motor can take, but do not want it to exceed 35 degrees advanced. They make special plates that help in this .