The Stovebolt Site Forums The Parking Lot Big Bolts Lengthen frame and move springs inboard?

So I want to lengthen my 51's 6400 frame by 3 feet, and also move my rear springs inboard.

looking to see if any one has pictures on what they used and how the lengthened their frame.

As for the inboard swap on the springs the dana80 rear I have for the truck is a bit narrower than the old two speed rearend, my plan was to move the springs in and then put airbags under the frame to the rear to do most of load work.

suggestions please

Are you leaving the wheel base stock or are you moving the axle back 3' ?

Mike B

thought was to move the rear back 1.5'

Moving it back 18" will make the truck a 6500 Series (179" wheel base) and will take you from two drive shafts to three.

If I was doing it I'd cut the frame in the tall section behind the carrier bearing cross member and add the 18" there. Others more knowledgable on this than me will tell you exactly how to cut it, weld it and plate it (if you need that help).

You may need another cross member as well.

Mike B

I run single drive shafts on 187 wheel base tractors with SPL250 drive shafts. But going to 3 drive shafts won't hurt anything. I do a lot of frame work. I wouldn't consider rigging an air ride. Buy yourself an air ride and throw away the original springs or get one off of an old school bus. This is a good one for a medium duty truck.

http://www.watsonsuspensions.com/Truck/Drive-Axles/DA-1700

You need to start right. Put the thing on jack stands and adjust it to where the frame is level. Then make sure what you add on is the same level. Also you need a straight edge to make sure the frame members are straight. If you not going to use the old suspension, I would just start with a bare frame rail. That way you would only have one splice instead of three. When you mock it up, pull a tape from a front U-Bolt and make an X to make the thing square. I have seen people create real nightmares when they just get out a torch and a welder.