The Stovebolt Site Forums The Shop Area Engine Shop 1939-1946 Chevy Frames Chopping and Welding

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?

Off road, chopping up frames....it sounds like you're hell bent
on hacking up you 70 plus antique trucks. I think you might
get more response if you were posting these questions to the
hot rodders over in the The HiPo Shop forum.
Denny Graham
Sandwich, IL

Denny X2. Why are you posting a frame question in the Engine Forum. More help in the proper forum.

All my Chev service manuals in those yrs say not to weld anything on the frame. Rivet only. They want the frame to be able to flex. Possibly welding compromised frame strength, also. No doubt alloys changed since then but those early frames were riveted. All repairs and side re-enforcing plates,(some mis-name them fish plates) were to be done w/ rivets, not welding. David

Those frames were not just simply 1018 mild steel, they were
an alloy and welding to them, as well as any metal, can cause
stress risers which eventually lead to fatigue cracks.
Probably wouldn't see much of a problem on a show truck that's
only driven occasionally, but if it's a work truck that you
put thru its paces every day, I'd bet you would have trouble
somewhere down the line.
Some guys get lucky and weld without post heat treat on
steering and suspension components and with light use, drive
the vehicles for years without incident, but a few do
experience failures at the worst times.
A good example are the rim centers that Charlie had fail on
him a while back. Improper welding technique resulted in
cracks at the weld root. Luckily he caught it before one let
loose out on the road at speed.

dg

If you insist on butchering up a frame, make the cuts at 45 degree angles and fish plate the joint for added strength. Getting things right so all the parts fit after the hack job has two possibilities, slim and none!
Jerry

There are a bunch of trucks with Mustang II fronts welded to the frames and you don't hear about them falling off. Depending on where you cut makes a difference on strength as well as how you cut it. When done right, it should last a life time. Sandwich the cut with same size plates inside and out side the frame rails, long enough to support the weight you plan to have on the frame. I wouldn't put the cut at a suspension mount point. I have seen the plates bolted in and have seen them welded in with spot welds through the center sections of the plates as well as the perimeter.

Joe