You will have to make everything from scratch then. One of the hardest parts about using another frame is cutting away the obstructions from the frame or the body parts like the inner fenders on the front. I have never done an S-10 frame under one of these trucks but God knows there are a lot who have. I forget the users name on here that did one, he only comes by once in a while and I forget his name. I think over at http://www.stovebolt.com/ubbthreads/...&Number=604050
there are a ton of threads on the subject.
Personally, I would find a stock frame, I replaced the frame in mine with another original just a couple of years ago and it took me all of about a day to find one, they are pretty common. There is NO SUCH THING as a "bolt in" or anything like that, it takes a bunch of modifications to both truck parts and frame, when it's all done if it's worth it, that is up to the owner some are thrilled with the result others aren't. I did the other very popular mod to these trucks, I put a Camaro clip. And this is the reason why I bought another original frame because I feel it was a mistake. First it robbed all the identity of the truck, you can install a Mustang II IFS and it just doesn't rob the identity like cutting that frame in half and welding on that big, ugly, clumbsy Camaro front end. Doing a complete frame "swap" is even worse, it just isn't an "old truck" anymore.
This is a PERSONAL opinion about MY truck not yours or anyone else's what you do is your opinion, I am just telling you how I feel about MY truck.