Rust removal on a large scale (frame), and body mount bolts

[Doober]

I may make some progress on this '78 before heading back to AZ yet I'm thinking at the best we'll be using some Eastwoods prep & paint, but I don't even know where to start. The frame was media blasted a couple years ago, and it's now covered in surface rust. There are a couple body mount holes to repair I believe (didn't pay very close attn. as we were working on just getting the body set on the frame). Does anyone have any tricks for something on this scale (pics below)? I also have to get body mount bolts, which brings me to my next question.

Everywhere I've looked online it says the body mount bolts are metric, but when I was at the dealer we came across a listing that showed standard bolts for the '78 (7/16" I believe), so I'm slightly confused... probably going to go back up there to try a little research. Does anyone else have any experience with the early G-Bodies?

This is basically what the frame looks like for the most part.

 

[melloelky]

their are tons of alternatives if you don't want to have it blasted again.eastwood is an execlent source,their house brands or any por-15 products are always sure to work out for ya.when i had my body media blasted i used ppg's metal prep along with red skuff pads to abrade the surface with said metal prep.what ever you go with,WEAR A RESPRIATOR/FILTERED MASK!!!
i had the worst headache for two days because i kept taking mine off to talk to people that stopped by.get the thick black rubber gloves from the depot or someplace too,no doubt.check out por15.com,if nothing else you'll have an idea where to go/what to do.
i replaced the bolts on my 78 elcamino and they were metric infact,two were shorter than the rest.tnt has them also.best of luck,i been there.

 

[barnym17]

Beleive it or not plain old rustoleum rusty metal primer over that surface rust then color of your choice in stops rust enamel..