Restoring my 74 swinger

I am restoring a 74 swinger. I will get some pics up soon. Its completely gutted. It has a brand new a/c firewall. Insides fenders are already painted. Underneath the entire hood(which isn't on the car) is all painted and almost finished body wise. It has a very straight body. It came with a rebuilt 225 slant 6 and 904. Both were removed to finish under the hood. There is only one rust spot that is pretty bad. It's the panel under the passenger side door. It's a rust whole maybe 3 inches long. I will really see what's going on when I get it sanded and primed. I don't own a sandblaster. I've heard bad stories about them warping sheet metal so I was thinking of going with an angle grinder and several polycarbide abrasive wheels and do the body by hand. It has the original paint from 74 and it looks real good just faded. I've been told that I could just paint over the old paint since I'm painting close to the same color, but I've never done that before. I have an 8 1/4 rear end that is completely disassembled. I'm wondering if that is a strong enough rear end since I'm changing the /6 and 904 with a nice v8 and an A833 4 speed Tran. Which would make the swinger more valuable, a 360 or a 383? Any help would be SO appreciated. I'm an auto tech and am just learning bodywork. I buy them, restore them, then sell them. I will post pictures tonight and I'm very thankful for all you great people that help so much. Thanks- Jeremy