Boulder off road does chevy vans all the time. They like chevys over fords. Everyone I have seen they just fab up some spring hangers and use leafs pretty simple and straight forward. If I was to do it from scratch I would use the factory spring mounts (coil) and 5 link it. Those spring mounts are a major part of the frame and is always looks a little odd when you do not use them and they just hang out there not being used. Either way chevy vans do look cool when converted. Good luck with it.
Derek
Those spring mounts don't have to hang out there unused...that's what a plasma cutter is for :coffeedrink: At least that's what I did with mine. They look big, but really aren't that substantial. I replaced mine with some coilover 'hoops' I made. I'll start a build thread at some point when I'm more complete, but the basics are:
Radius arms up front similar to SuperDuty
2.5" King CO's
GM Dana 60 cut/sleeved into drivers drop low pinion
Alcan rear spring packs
Bilstein 7100's in the back (and for steering stabilizer)
35's on H2 wheels, no fender trimming (front moved 2" forward)
5" suspension lift over stock (10" total travel, 5" UP, 5" DOWN)
T-Case will be Ford NP205 divorced behind stock 4L85E trans.
Homebuilt driveway build...
Oh yeah, my van has a Duramax ('06 Savanna). Not sure how it'd work with a gasser in there.