1948 GMC frame questions

[DS3685]

Hi guys Im looking for some information and possibly photos of shortening a LWB frame down to the SWB frame. The customer wants to shorten the frame doesnt want to do an s-10 swap or look for a SWB frame....very adament about using his....customer is always rite....Anyhow Ive been searching and reading and all the posts seem to all start with good info and then it turns into the cut here dont cut here do a straight cut dont do a straight cut...or the debate of not shortening the frame starts....Does anyone have any solid info on the best place to take the frame section out or pictures? Im just looking to do some research and gain as much info as possible before I start the project. Thank you

[dwcsr]

Get your self a copy of the assembly manual so you have all the frame measurements. The difference is between the cab and front rear spring perch. The issue is that its an A frame and cutting 10 inches out to shorten it leaves your front section and rear section uneven where you want to weld.You need to pull in one section and push out the other. As for what type of cut I have always used (40 years now) a half diamond cut and plated with a full diamond shape on both sides if possible.

[mr48chev]

One of the guys over on the 67/72 side posted a diagram suggesting lapping the 48 t frame at the cut.

You will have to come up with your own measurements though as the frames are different.
I know that I for one would never get that diamond shape cut close enough to fit things together without a hassle. I'd still plate and probably box the frame though.


This is my GMC frame that I am using under my 48 to build the stretched cab on.
[[URL=http://s173.photobucket.com/user/mr48chev/media/0000%20Buildiing%20the%2048%20%20Chev%20pickup/006.jpg.html] you can see the extra crossmember that was added in front of the regular crossmember when they built the frame. You probably don't need to remove that but I' make the cut in front of it and then redrill the holes for the cab mounts back where they need to be. The rails are pretty parallel right there so it shouldn't be a big hassle.