Ad Engineering is in CA, They don't officially have a 4X4 kit but they've had some customers do it.
This is what their site says.
Q: Do you have a kit so I can use a 4wd frame?
A: Yes and No. Our kits are designed to work on 2wd frames. The main issue with the 4wd frame is the front frame horns which are different than the 2wd. Minor modifications to your truck cab and our kit may be necessary. We stopped offering the 4wd option because of numerous little differences on the front frame horns that kept popping up in the different model years of S10 4wd production.
http://www.ad-engineering.com/FAQs.html The place you might be thinking of in the Midwest Scott is E-Z Chassis swaps I resell their kit but they also don't officially have a 4X4 kit, but I'm sure they'd be happy to talk to you about it. The owner there is Ed, and I'm sure he'd be happy to talk to you about it, tell him Mongo sent ya'.
http://www.e-zchassisswaps.comSteve
