4WD Conversion Method??

[72longbed]

I found an article in an old 4 Wheel and Off-Road the other day that looks mighty interesting. This guy converted a 72 C20 to 4x4 by simply putting the rear axle under the trailing arms, and constructing a front suspension very similar to a 1978 Ford F150 4x4 with Radius arms and coil springs. He removed all of the stock front suspension down to the engine crossmember. He used an NP205 / Turbo 350 tranny, and a Dana 44 front axle out of a Chevy pickup.

Has anybody ever seen or heard of this type of conversion? Do you 4x4 experts think this is a safe and workable solution for us guys who have put way too much time and money into our 2WD's to sell them but need 4WD capability? From what I read its all "bolt-on" changes and can be reversed very easily.

I'm seriously considering making this change with the price of 70-72 4x4's being so high and me not willing to put another 3 years into getting another truck "just the way I want it".

Anyway, just thought I'd run this by the crowd that knows 4x4's to get some opinions.

Thanks,
72longbed

[1FaastC10]

i've got a buddy with a '68 Longhorn who asked me yesterday what it would take to convert to 4x4. initially i suggested just getting a K20 chassis, complete and put the body on. but, with the truck being a longhorn, the K20 chassis is too short. i'll be following this thread to see where it goes. anybody ever converted to 4wd using a 2wd frame as a start?

[4x4Poet]

I remember that article an cut it out for my "file." It was a white K20, right? He welded some sort of bucket-shaped perches for the coils onto the straight axle D44 and also welded on the brackets for the f@rd radius arms to both the D44 housing and the frame. The rear radius arm brackets were custom. I think it came to about a 6" lift. He had 36" tires underneath it. It looked great and well done. I'm not sure about stable or a good ride, though, for obvious reasons. I also wondered about the strength of the single u-bolt in an over the axle configuration.

The article stoked my interest in converting my C10 to 4wd, but I think it would be easier for me to swap the pristine C10 body onto my K20. For a 4x4 with a 6" lift, the four-wheel coil ride on that conversion must have been saaammooooooooth.

[72longbed]

I spoke to the guy who built that truck. Yes, it's a white C/K 20. He says the ride was incredibly smooth. I think he said that everything on the front axle was 'robbed' from the Ford front axle and bolted onto the Chevy Dana? The spring cups were stock Ford? He did weld together the bracket for the rear of the Radius arms but it was bolted to the frame of the truck.

He said that if he were to do this type of project again, (sold the white truck), that he would look into air bags for the front instead of coils. Air bag technology and applications have improved dramatically since 1997 when he first built it.

4x4Poet, you said that the single U bolt on the rear would concern you, why? I'm thinking that if I was to do this, I would weld another spring perch to what is the top of my axle tube now, right above the stock perch, and when it is put under the trailing arm, this would be between the trailing arm and the axle. Then put the U bolt up through from the bottom with a 3/16 steel plate on top of the trailing arm, then the nuts. Would this still worry you or is there a safer/stronger way to do this?

Thanks for the input guys,
72longbed

[4x4Poet]

I don't know if the single rear u-bolts in axle-over configuration wouldn't be strong enough. I should have only said that the article did not convince me that his trailing arm "flip" with a new top axle perch would be strong enough using the single u-bolts for heavy duty 4x4 use. I don't have the expertise about the flip and so I am left wondering, that's all, After all, stock 2wd 3/4 ton trucks use the fat single rear u-bolts with no problems. I couldn't rightly advise you on the spring perch choices, though I'd try to use 1/4" steel, if feasable.

Interesting that he might not use front coils again. The only thing I can think of is 4-coil trucks can be a little bouncy in a gentle way. Maybe the lift, higher spring-rate coils, front straight axle, and 36" swampers all contributed to more bounce than a 2wd all-coil truck.

[ryanroo]

i might be wrong, but aren't 2 wheel drive and four wheel drive frames very similar? my dad and i talked about this a few years back, and i think the front of the frame is the same, with all the holes for the 4x4 spring hangars and stuff punched already. if this is true you could just go rob the hangars from the junkyard and do some careful measuring to place the shackle mount then bolt the hangars up and use the stock leaf spring configuration. it would seem simpler this way, but i have never really been around a 4x2 so im not sure. i don't know anything about the frames on a longhorn, i would assume the extra length is all in the rear of the frame so the same theory would apply but again im not sure on any of this.
Ryan

[1972]

I saw the article also and that's similar to what I have planned. I want to do the flip in the rear and use a 3" block, possibly swapping in a 9" rear. In the front I want to use a Ford D44 that already has the radius arm mounts on it and some lifted coils, possibly into my factory coil buckets. I was thinking I could use a divorced 205 from a Ford, that way I can still use my 2 wheel drive transmission.

[ABHaulR]

my sub is a 2wd conv. i flipped the axle under the trailing arms added 3 inch blocks. 10 1/2 inches of lift. removed the original front cross member added a v-8 conversion motor mount. hung front spring hangers and shackle mounts for the front springs. used a od trans and a divorced transfer clocked for ground clearance. it rides good. the single u-bolt was scrapped for a dual bolt setup.
Dwayne

[Canadian694x4]

ABHaulR would you have any pics of the under side of your burb showing your mods?

[ABHaulR]

my camera is in the shop rught now, but when i get it back i'll shoot some pics.
Dwayne

[racerx]

Will We, The Guys With The Wild Hairs, Have To Put The Box Forthe Transfer Case And Shifter In Or Can We Just Raise The Body?

[MAC67]

ive done a 2wd frame converted to a 4wd although it was with an 87 shortbed , i would strongly suggest finding a 4wd frame , i did what ab up there did , measured , measured , then did some more measuring so it would run true up front and mounted all the hangers and slung the front axle inderneath it ,i have heard of the four coil spring set up , there was a 65 or so gmc shortbed done once but it had a leaf spring front , a buddy had a video of it from indy years back , he said the guy pulled up to do burnout runnin like 44 inch tires , he did get them broke losse but with the coil rear it squated hard and hooked really nice , a guy a few towns over from me that i know did a 2wd to 4wd conversion but again he used leafs up front he said it rode realy nice but the rear seemed way to spongy to haul anything really heavy , it sqauted it to easily

[ABHaulR]

mine is that way, kinda soft in the rear, rides great though. i'm working on a 3 link setup for mine, where the wish bone comes to the rear end you put a pad for a removeable aigbag setup. put it in when your going to tow then take it out or just leave it in. that way youve got the best of both worlds. when i start the install i'll get alot of pics.
Dwayne