I am in the process of getting a fifth gen el camino (78-87) and need to know about what the average weight is with a smallblock v8 and auto trans. I need the vehicle weight not the gvwr.

Also with stronger components would the 7.5 rear hold up to a 400 + hp engine, if not what rears would interchange (bolt in).

Man, I wish you had gotten an answer to your questions, because those two questions were exactly what I was wanting to ask. JB  

the rear will last till you really get it to hook. if you plan on leaving hard with a set of sticky tires you rear will give up the ghost. thing is you'll not know when. if you get away with it once... don't get asured it'lkl work that second time. have a chase truck with trailer accompany you to the track, just to be sure. good luck. look for an 8.5 out of a buick gn. or a cheap  conversion s-10 zr2 8.5 (however the truck rear will not be a direct bolt in. you'l have to fab mounts.