I have converted 2 vans, both Chevy, an 81 and an 87. The 81 was easier because of the style of pitman arm, although I couldn't find a suitable style to bolt on, I had to fab my own pitman arm. On the 87 with the pitman arm swinging side to side across the van vertically, I just used the stock one. Use a mid 80,s 4x4 tie long tie rod for the drag link. Was years ago, but can't remember how I attached them together, I know I used the stabilizer bolt hole to bolt to the pitman arm ball joint, you will have to get a machine shop to cut the taper into the hole. Then cut the tie rod and machine new threads to make the unit the right length using the tie rod coupler and a short tie rod end. Anyway, getting too technical. It's a big job, first one took me 100 hours, the 87 took 80 hours once I had the swing of the plan. Chevy's are unibody so all the suspension brackets have to be welded onto the sheet metal, not ideal. If you use a 2" lift spring from an 80's blazer it's about right and it'll fit 33's nicely. But you will only have like 3" of suspension travel. In '78, '79 you could buy a 4x4 van from the factory. They were aftermarket conversions sent out by the dealer and they were horrible. If you ever get a chance to look under one, you'll wonder how GM ever allowed it! Also, you mention you have 1 ton running gear. On both mine I used 3/4 ton (8 stud wheels), but used a van rear axle so it bolted right in without mods and was the right width. I know blazer and suburban rears are narrower than the front, not sure on PU rears. Van ratio was 3:75, Dana 44 front was 3:73 I think. Acceptable difference.
I will do another one one day, but it will be Ford. Full frame, all the brackets will bolt on. Look at one when you see one. It looks factory, solid and strong with lots of travel. Hiring a shop to do a conversion will be a fortune. They come up for sale once in a while, just watch Craigslist. Might be easier to buy one already done. Just make sure a 4x4 shop checks it out to make sure its not a hack job if you go that way.
Cool. How much have they quoted you if I may ask? For a full 4x4 conversion?
I have converted 2 vans, both Chevy, an 81 and an 87. The 81 was easier because of the style of pitman arm, although I couldn't find a suitable style to bolt on, I had to fab my own pitman arm. On the 87 with the pitman arm swinging side to side across the van vertically, I just used the stock one. Use a mid 80,s 4x4 tie long tie rod for the drag link. Was years ago, but can't remember how I attached them together, I know I used the stabilizer bolt hole to bolt to the pitman arm ball joint, you will have to get a machine shop to cut the taper into the hole. Then cut the tie rod and machine new threads to make the unit the right length using the tie rod coupler and a short tie rod end. Anyway, getting too technical. It's a big job, first one took me 100 hours, the 87 took 80 hours once I had the swing of the plan. Chevy's are unibody so all the suspension brackets have to be welded onto the sheet metal, not ideal. If you use a 2" lift spring from an 80's blazer it's about right and it'll fit 33's nicely. But you will only have like 3" of suspension travel. In '78, '79 you could buy a 4x4 van from the factory. They were aftermarket conversions sent out by the dealer and they were horrible. If you ever get a chance to look under one, you'll wonder how GM ever allowed it! Also, you mention you have 1 ton running gear. On both mine I used 3/4 ton (8 stud wheels), but used a van rear axle so it bolted right in without mods and was the right width. I know blazer and suburban rears are narrower than the front, not sure on PU rears. Van ratio was 3:75, Dana 44 front was 3:73 I think. Acceptable difference.
I will do another one one day, but it will be Ford. Full frame, all the brackets will bolt on. Look at one when you see one. It looks factory, solid and strong with lots of travel. Hiring a shop to do a conversion will be a fortune. They come up for sale once in a while, just watch Craigslist. Might be easier to buy one already done. Just make sure a 4x4 shop checks it out to make sure its not a hack job if you go that way.