I wouldn't worry about getting a small block to fit in the '46. I have a '46 1/2 ton, with the original straight axle and springs. I stuffed a 383 cu. in. Chrysler big block in it and didn't have to cut anything out of the way. I have the 727 Chrysler trans. and rear end also. The floor board fit fine and even the louver inner fender panels, fit back, in place. My steering gear is not stock, so that may or may not be in the way on yours. I used a Maverick stock radiator and still have the original radiator support in place.
