Try this:
http://www.usbodysource.com/Install%2047%20chevy.htm
IMHO an S-10 frame is too light for 1 -1/2 ton truck.
Here's what I'm doing on my '57 Burb..
Mounting it on a '00 GMC chassis with Vortec running gear
Mounted the body today but still need to move the rear end 3" forward so it will fit properly.