The Stovebolt Site Forums The Shop Area The HiPo Shop 1939-1946 truck frames

I'm looking to build another truck from the parts i already have from another project, my issues is looking for a 1940 half or 3/4 ton frame (I just stated looking for one so one is bound to surface but...if I decide otherwise) The '40 3/4 ton frame is 122-ish inches and the 41 3/4 ton is 125-ish inches. To save myself $ and time looking for a quick frame, I was thinking about cutting a few inches off the '41 frame to match the wheelbase of the '40 and I wanted to know, how I should do this or if this is a good idea?

I am not commenting on if you should or should not do this.However I have cut a few frames in the past,but not of this year.If you do cut a frame,break the vertical line. Another words cut about half way up the side (vertical) then cut horizontal at least the width of the frame.I go more if I have room.Then cut vertical ,to finish the cut.This helps prevent cracking,and gives more welding surface.I also like to put a fish plate on the inside over the weld.The fish plate is rectangular in shape,but I cut the ends so it has a point at the centerline on both ends.so it looks like this
<__> .then I weld around it. Cutting the ends break the vertical line.Doing the joint this way makes it a strong weld joint as long as your welds are good.The last one I done was a 1988 chevy 4 x 4 that was being restored.I subbed the Back half of the frame,(behind the cab) with one from another truck.

I not really sure how to ask this but for lack of a better way, what part of the frame would you cut because the width changes as different points and also what I do about the length of the drive shaft, will a machine shop be able to shorten it? I plan to use an S10 5 speed behind a 216, so don't know what I'm going up against really

A little more info about your planned project would be helpful. V8 conversion? Looking for independent suspension? Jacked up, dropped down. Air bags. It will help us provide more relevant information.

I have a 1946 3/4 Ton GMC frame (no suspension, just the rails), but I'm a long ways from you.

Its a pretty straight forward build I'm building a completely stock 1940 truck with a 216 engine and T5 trans except I cant find a '40 3/4 ton frame so I'm thinking about chopping a 1941-46 frame down to size, its about 3 inches

Do as Metal Shaper suggests. I would think a few inches behind the cab would be the best spot to do it. Sounds like a fun project.

Just as horsenaround said most likely the best place to cut it is behind the cab.I don't think taking out 3" or 4" will be to much of a problem even though the frame is tapered .One other thing to keep in mind is as long ,as the same amount is taken out on both rails of the frame,(say 3") the cuts do not have to be in the same place on each rail,but the amount removed does have to be the same.When I cut a frame I always make sure the frame is square before I start,and scribe a reference lines to work my measurements from.

Great cutting and welding info!

does anyone know how you can shorten the drive shaft, will a machine shop cut it down or do I have to find something?

I have cut them as well.Its not to hard to do, but its best to cut the shaft with a lathe. Most machine shops will shorten them for you.
I saw a 1946 Chevy truck frame on eBay today.

I saw that frame too. I think, I'm willing to travel for a '40 frame but there are several '41-46 frames locally that I can pretty much get for free, so that's where my question/idea for cutting and welding came from