90 crew cab dually

[87bbcs10]

I have a 90 crew 2wd dually with 454 and 400 trans. I am wanting to convert it to 4x4 i have search the forum already found few threads but most are swapping frames over i want to swap in the axle and keep my stock frame. I haven't found a really good detailed swap that has all the pics and tells all the details on parts and how to do the swap. If anyone can post a link that is well documented and has good instructions on all the info that would be great. Or anyone that has do this that can chime in and guide me though it that has pictures that would be great as well. thanks
Tony

[cableguy0]

The problem is that 2wd and 4wd frames are completely different. The mounting of the leaf springs is a big issue. Plus you will have to add a crossmember to the frame once you remove the stock crossmember and A arms. Its really not worth the amount of work especially considering you could fairly easily locate a 4wd truck. There is also the issue of getting the transfer case mated to the transmission. Your 2wd transmission wont work without completely tearing it down and swapping the output shaft. You will be doing a lot of fabrication and welding on the frame. Not saying at all that it cant be done but it would likely be cheaper to just find a 4wd truck in the first place.

[1968vetL-71]

I did this exact swap on my 91 crew cab. I've read tons of threads that say it's all bolt on, it's all the same stuff, frames are the same......blah blah blah. 4wd crossmember will not bolt in directly ( I built mine ), shock mounts different, spring hanger holes were not the same and other small odd n ends. When I have some time, I will surely start a build thread. I took pics of everything along the way solely to document that it is NOT just a simple bracket and direct hanger swap. I would be glad to help a fellow enthusiast out. All in all it wasn't that bad. If my crew cab wasn't rust free and low mileage I wouldn't of done it for sure. I even located the 1 year only VSS np205 tcase, and everything off a 91' V30. Good luck with your build. I'm sure it will be worth the time and effort.

This is the lowly R30....

[87bbcs10]

I have a 4x4 tranny and t case and I know i got to change the cross member that Dont scare me. And around here it not easy to find a 4x4 crew cab long bed that runs and drives for reasonable price. I can get all the swap stiff cheaper than buying a 4x4 Cuz I trade for the stuff that's how I got the truck. If can pm me so can ask you questions.

[1968vetL-71]

And now my V30!!

[87bbcs10]

I don't want to go crazy with the truck I just want it to be 4x4

[1968vetL-71]

Got ur pm. 1/2 or 3/4 ton spring hangers will not work. Frames are taller on a 1 ton. The front hangers on the rear are different from 2wd to 4wd also. I swapped the front on the rear hangers and I also used ORD shackle flip hangers on rear. Shock brackets should work up front. Try the board here for any parts you need or a local pull a parts. I found a guy parting a 91 V30 crew cab so all my stuff was off the same rig basically. You won't have to worry about the electronic speedo as I did with your 90. Where are you located? I have a complete crew cab 4x4 frame I might possibly part or sell.

And I didn't go crazy with mine.... It's just a small lift and tires. Perfect size for a crew!

[87bbcs10]

I'm located in northen Ohio a so I couldn't use a half ton cross member and hangers just for the front? It has to be one ton stuff

[andrewmp6]

The 1 ton frame is different you need a 1 ton crossmember and hangers for it.

[87bbcs10]

Well that sucks

[1968vetL-71]

Pm'd ya.

[joe231]

I put a 3/4 ton crossmember into a 1 ton truck, they were both 4x4 and the crossmember bolted right in. I believe the front of the frames are all the same height, the difference is from the cab back to the rear axle. Nothing is bolt on from 2x to 4x so you can use hangers and crossmember from whichever trucks you can find....1/2, 3/4, or 1 ton. The rear spring spacing is narrower on 1 tons though. You can reuse the front hanger on the rear springs and do a shackle flip to raise the rear.

You can get aftermarket front spring hangers and front upper shackle hanger (FUSH) from diy4x.com as well as a shackle flip.


All it takes is patients and hard work and you can accomplish anything

We currently have four 1 ton 4x4 crews and a 3/4 ton 4x4 suburban sitting at our house along with a 66 2wd pick up (same basic frame in the front as the 1/2 ton square bodies, with some differences) I am willing to help with measurements and pics if you need them.

[kwmech]

With the correct 205 and adapter you DO NOT have to pull the trans and replace the output shaft. However, you will have to put in and adapt a speed sensor for the fuel injection unless you leave it where it is on the 400. May get quirky in low range though

[87bbcs10]

I already have a 400 that is paired with a t case so I Dont need east time with the 2wd tranny.