Welcome 56GMCR,
What about going the drop spindle route with disc, springs etc. There are quite a few good manufactures out there that just make the job so darn easy. I did our 64 burb and it was just unbolt old and bolt up new...slick. Slammed the heck out of it and the ride is sweet. You'll probably have to notch the rear frame at least unless you do something even more drastic. They have those kits also and it will give you more clearence ie, better ride in the rear.
Anyway, welcome! Oh, and good deal you got...sweet!
