LWB frame question

[Zach_H]

What would it take to put a 1950 3/4 lwb frame under a 1949 1/2 swb truck? I assume everything from the rear of the cab forward would be fine correct? I'm really just trying to see how the frame could be shortened in the rear to accomodate the swb bed. I looked around on here and the hamb, but I couldn't find anything. I'm also on my phone trying to find all of this info, so there is a good chance Ive overlooked it. Any info or a link would be greatly appreciated.

[OrrieG]

The Factory assembly manual will show both frames including perch locations for the rear springs. If you are lucky the factory punched the frame in both locations for the rivets and rear cross member. Then all you have to do is grind out the rivets and relocate with bolts, cutting off the extra length. If not the manual gives you the locations of the holes (I am basing this on what my 55-59 manual shows) you just need to measure and drill using the perches as a template.

[dwcsr]

I'm not 100% on this but I thing the major difference in the frames is thickness of the rails. Most everything else should be the same as far as swapping frames. Provided you go short to short or long to long bed.

[mr48chev]

The 3'4 ton rails run more parallel to each other behind the cab. not a bad thing if you intend to shorten them.
It may also help a bit if you plan to run fat tires on the back as you shouldn't have frame rail clearance issues.
If I can be so bold as to ask, is there a reason for swapping frames other than the half ton frame is shot?

The only issue that you may run into and it isn't a real big one is that some of the bed mounts may not line up with the frame and you may have to weld some tabs on the sides of the frame rails in the back to make things fit right. If you are capable of shortening the frame that shouldn't be a real issue. Measure, make a bracket, weld and bolt the bed in place.

[Zach_H]

Originally Posted by mr48chev

The 3'4 ton rails run more parallel to each other behind the cab. not a bad thing if you intend to shorten them.
It may also help a bit if you plan to run fat tires on the back as you shouldn't have frame rail clearance issues.
If I can be so bold as to ask, is there a reason for swapping frames other than the half ton frame is shot?

The only issue that you may run into and it isn't a real big one is that some of the bed mounts may not line up with the frame and you may have to weld some tabs on the sides of the frame rails in the back to make things fit right. If you are capable of shortening the frame that shouldn't be a real issue. Measure, make a bracket, weld and bolt the bed in place.

Well, when I bought the truck it had a half completed 79 trans am sub under it. I got the truck for a decent price, so I went ahead and bought it anyway. I ended up selling the frame to a friend and making half of my money back. I had always planned on putting a mustang II suspension under my AD when I found one, I've had a very difficult time trying to find a frame close to where I live. I came across a frame on craigslist a few weeks ago but it was already sold, and this is the only other frame that I have found within 300 miles in the last two months that I can buy. I'll probably go down this weekend and double check a few measurements on the frame, and check everything out. If anyone else has any information, please let me know. Also, thanks to everyone who replied!

[Fred T]

The 3/4 ton frame is longer and the steel is a little heavier. Shorten by cutting out a section behind the cab where it's straight. The spring mounts are different, but can be swapped.

Keep looking for one locally. It might take a while, but they are out there. And if you find a long frame with a decent bed you could make it a long bed 1/2 ton.