1949 3600 to 3100 conversion questions

[49'3600]

Hi all,
I am new to this forum and forums in general so i apologize in advance for lack of knowledge... I recently purchased a 49' 3600 here in Tucson, AZ. No significant rust, original motor and trans, straight cab, but still a total project. It currently has a flatbed that looks to be a made-to-fit bolt on type deal. I have found a bed off of a 3100 nearby. My end goal is to make this truck have the look of 3100 in a sense. Then get to the mustang 2 front suspension, 383 stroker, ford 9 inch ect... Most of which i already have. I have been told the s-10 frame is the way to go but i would rather not go that route. This frame is in excellent shape and i am not afraid to cut, weld, box, ect... My first question on this build is at the rear. From what i have read, the difference between the 3600 and 3100 is 9.75 inches in frame length / wheel base?? Also is the 3600 frame is more narrow at rear as the leafs are mounted on the side of frame rail rather then underneath??? If the rear is more narrow does that mean the front is as well??? I have little knowledge of these trucks but i am itching to learn. Thank you all in advance for taking the time to read this. Any advice is greatly appreciated. I am pumped about this cool old chev and looking forward to hearing from you all!

[Hampshire]

I did it in my build thread and crossfire84 did it in his build thread, too.

http://67-72chevytrucks.com/vboard/s...d.php?t=530662

I can't remember exactly how much we cut out, but we both did the same kind of cut "Z" cut with boxing. I also reversed my leafs springs (what was left of them) which centered the rear wheels in the fender opening by moving the axle back a little more than an inch.

AD frames are fine. If your frame is wasted, perhaps that's the time to look at an S10. 3600 frame is slightly taller than a 3100 and the metal is .050 thicker, so it's a bit more robust. With boxing and cross bracing as needed, it will work fine.

[49'3600]

Thanks for the reply, the z cut is a good idea as well.

[69l46vert]

I did the same. There was a hole in the frame you can see in the pics that I used for the center of the cut.

The front of the frame is the same between 3100 and 3600 until about the rear of the cab.

[49'3600]

Sweet thanks, how much exactly did you shorten it?

[mr48chev]

It should be the 9-1/4 inchs that you mentioned before. 69146Vert showed the correct way to shorten the frame and give the splice the

The only issue I see is that when you mount the bed you will either have to move the brackets in to match the frame on the rear piece of the bed or fab some brackets off the frame to bolt the bed to. 3600 frames go pretty much straight while 3100 frames spread out at the back.

[Hampshire]

The only issue I see is that when you mount the bed you will either have to move the brackets in to match the frame on the rear piece of the bed or fab some brackets off the frame to bolt the bed to. 3600 frames go pretty much straight while 3100 frames spread out at the back.

It's really pretty easy. Note I made use of 8 mounting points - a 1/2 ton uses 6. I used the stock rear cross piece I had & bought three new cross pieces (2 center and 1 end cross piece ) from Mar-k. After mounting at all four corners and leveling by minimally adjusting the wooden blocks, I added the two center pieces and adjusted the wooden blocks to fit.

[69l46vert]

Originally Posted by mr48chev

The only issue I see is that when you mount the bed you will either have to move the brackets

Very true. you have to move the brackets on the 1/2 ton rear cross sill in about 5" on each side in order for it to bolt to the more narrow 3/4 ton frame. Keep in mind too that a 1/2 ton rear bumper and brackets won't bolt right up either unless you add make 5" stand offs/bracket adapters on each side of the rear of the 3/4 ton frame. The 1/2 ton frames are about 10" wider at the rear where the bumper brackets bolt up.

edit: Sweet looking bed Hampshire. Wow, that is really nice. I want those taillights too.

[mr48chev]

3100 frame is 46 inches across the back end. 3600 frame is 36 inches across the back end. Outside of mounting the back of the bed the straight frame rails from the back of cab back make life easier when it comes to any chassis work. you might do.