Tightened the pinion nut... noise reduced. So it IS the rear and not the trans! Problem now is that I have no idea what I need to tighten that pinion nut to. I counted turns when I did the pinion seal and put it back but apparently missed the mark. May have to pull the pumpkin to check it out. I guess the contact pattern would be what to check? It sounds pretty decent now so I may leave it alone...
Also put 62 jets in the front of the carb instead of 54. It’s much happier now.