I have a 51 Plymouth coupe with essentially the same suspension. I will tell you that with even the original flathead 6 in it wheel hop is something else in a corner. You might want to consider redesigning that rear suspension. the front suspension has some issues as well that can be addressed easier than a clip job though. Relocating the upper shock mount and a rack and pinion setup fixes most of it. Fatman's makes a rack kit. Discs are easily added. In the front, with proper backspacing I can get a set of P255/60R15's in there. Just s set of rollers I have on hand. Probably going with 17's for a better tire selection. In the back I can squeeze 295's easy, probably 315's if you get the backspacing right. No too sure about a 53 wagon though.