Suburban 4x4 frame swap

[cal30_sniper]

I'm contemplating a 4x4 conversion on my C20 Suburban since I already have it torn apart for everything else I'm doing to it. I've already decided that if I decide to do this, I'd rather do a frame swap than attempt get all the 4x4 stuff hung properly on the front frame.

I've had two options pop up that are the same asking price, I was wondering if anyone here might have some input on pros and cons. The first is a late 70s K20 Suburban. The body is rusted all to bits, but the frame looks solid. It's got a Dana 44/14Bolt axle combo with a NP205 transfer case. The second option is a K30 SRW crew cab with a Dana 60 front axle and round pattern NP205 transfer case. I want to swap one of these frames underneath my 86 C20, with a round pattern NP205 or NP241 to mate up to my NV4500 swap.

I realize that the K30 frame would have to be shortened at the rear to get the proper wheelbase, and it is my understanding it's also about 5" too short between the axle and the rear bumper. I reckon this could be solved by cutting and shortening the frame ahead of the rear axle, and moving the rear axle forward a bit to lengthen the frame behind it. If I went this route, I'd get the round pattern NP205, Dana 60 front axle, beefier springs, and bigger 1-ton frame.

If I go the K20 route, it's a direct frame swap, but I get the weaker frame and smaller axles/springs. That, and I still have to source a round pattern transfer case.

Any input on the cost/reward benefit for going the K30 route? Would I be better off just getting the K20 and upgrading the axles/transfer case, or is the larger frame really worth it.

I tow a good bit with this thing, up to a 10,000lb bumper pull enclosed trailer. I'd like to keep my towing ability, while expanding my offroad capability a bit. I don't even plan to lift the truck, I just want something with drivewheels on both ends. Of course, I could always get the crew cab and keep it as a crew cab, but I really would prefer to have a Suburban body.

[SunSoaked]

K30

[cal30_sniper]

I didn't mention it in the first post, but a K30 based frame would also allow me to mount a larger trailer hitch on the frame as well. I'm currently limited to 10,000/1250 with a weight distributing hitch by the available hitches for the slanted Suburban rear frame. With a straight truck frame, I could step up to a larger Class V receiver hitch.

I've already got a 14BFF rear end, hydroboost conversion, a big block, and NV4500 trans. I just don't have the frame and springs that the 1-ton does.

[SunSoaked]

K30 X2 in that case.

[sweetk30]

frame shape / bends / dips are all different from suburban to pickup frame .

the only real frame advantage is the middle section is taller/deeper than 1/2 and 3/4 ton frames . after the frame humps up at the firewall forward and rear suspension there the same shapes .

so to put a suburban body on a c/k truck frame will require LOTS of MODIFICATIONS

[mongocanfly]

soon as I get done getting what I want to keep off it ,ill have a 3/4t 91 4x4 burb frame to get rid of...

[KeithT712]

Even better! Should be a pretty straight forward swap then, I've always wanted to do a nv4500 swap in something. Did I see right your doing an 8.1 swap also?

[cal30_sniper]

Yep, the 8.1 is sitting on the stand waiting to go in. I ported the heads, and dropped in a GM Performance 454HO cam with dual valve springs and comp roller rockers. Ported the intake also. Along with a free flowing intake and headers, with my special blend of tuning, it should be stout.