If you are doing this swap do you have to use a long bed frame? Or is this a long bed body? Also did they even make two different bed sizes?
you dont have to use a longbed, although it works out on the wheelbase right away, I used a shortbed reg cab s10 and a trick another guy showed me.
here is mine, you cut off the last 11" of the frame, flip it over, and move the leaf perches back 9.5 inches (they are riveted in)
after flip and moving the axle (note where the bumpstops are)
welded and fishplated
I got the idea from another guy who did the same.
a longbed driveshaft fits perfectly after that, you dont need to have one made.
there are TWO advantages to this way over stretching the the frame at the joint under the cab (which can also be done, or shortening it there with an ex cab)
1: the leaf perches arent hanging lower than the frame any more, so any bolt on link setup works without the "short" bars. I have an ART roadgrater on mine.
2: you can move the gas tank back and up with a gas tank relocator bracket and its no where close to ground or the axle any more.