47-55.1 Flipping the rear end

[mobileortho]

You know one thing leads to another. I knew the bearings were worn on my 3600 so I replaced them. In the process I decided to lower it some more by installing a c-notch. Got this set off EBay. They’re supposed to bolt on, but I’m thinking I should mount them on the opposite side and weld it in so that section would be boxed for additional strength. Thoughts?

[nvrdone]

personally, I wouldn't trust it being bolted in. the frame does flex and I can see the bolts coming loose. id weld it in. I hope those plates are only for one side of the frame. id want plates both inside and outside on each side of the frame rail.

[mr48chev]

I'd think most guys pick up a short length of 4 inch sch 40 steel tubing and a piece of cold roll flat bar The same width of the frame and make their own notches.

I've got a buddy who built a lot of rods back years ago and he would slice a piece o tubing that was real close to the with of the frame in two. and notch then trim it so that the ends tapered down over several inches so that he had about a 6 inch flat piece over the notch with it tapering down to the frame on each side as a reinforcement to the frame.

[jweb]

I would use a weld in c notch meant for these trucks, it will box in the frame and be solid like this:
https://www.classicparts.com/1947-53...tinfo/93-314A/

[mobileortho]

Originally Posted by jweb

I would use a weld in c notch meant for these trucks, it will box in the frame and be solid like this:

I like that , but it looks more like it's made for a 3100. There aren't a lot of options for the 3600.

[dsraven]

-decide what your notch should look like and how much suspension travel you will need for your ride height. some guys will try hard not to "butcher" the frame and will do a smaller notch only to find out their axle bottoms when going over bumps. then a bunch of work goes into engineering a stiffer suspension or snubbers to absorb that. it would be better to install a bigger notch and raise the bed floor a bit than under-build the notch, only my opinion there. it would be good to also center punch a mark on the frame where the axle centerline is so you can duplicate that after. also, just for goggles, take a look at how some of the huge notches are built, where the frame is strategically "lopped off" and a new section is welded in. there could be some merit there if a smaller notch is required, just less "lop" and therefore less raise for the bed floor.
-grab some cardboard or poster board. something stiff without the corrugations as that stuff flexes and bends too easily.
-make a template of the frame in the area where you want the notch. ensure to go long enough ahead and behind so the frame is supported well. you can get pretty accurate by holding the cardboard tightly against the frame and then using a hammer to tap and cut the cardboard using the frame flange as an anvil. pay attention and decide how the fit for the boxing plates will be so the template will fit (1) inside the frame flanges, or (2) fit outside the flanges and essentially make the frame "fatter" in that area and will be the exact same size as the frame. it's all about the fit here. if you fit wrong and then weld it in and decide to grind the weld down for a nice finish there could be nothing left of the weld. plan accordingly and/or grind the edges to a taper where it fits against the frame flanges to allow room for the bead of weld and the weld finishing after. this link shows a few ways of boxing. just remember to leave room for the weld and do stuff slow, with bracing, so the frame doesn't bend.

https://www.hotrodhotline.com/conten...icle-jim-clark


-ensure to make the appropriate cut away above the axle center line for the notch. remember that the welding shop can easily bend up some sheet to match the notch cutaway OR they can slice some tubing and fab up a rounded notch. a notch with flat top could also hold a bump stop, not as easy on a rounded top notch. factor in the thickness of the bump stop. the other idea for a bump stop is to install another bracket on the frame and diff housing for the bump stop. no bump stop = dental work after a speed bump.
-take the template to a welding shop with some sheet metal tools, like a break and shear, and have them make a couple of pieces for you out of cold rolled flat stock. that way there will be no mill slag on the sheet that would require removal before welding in. have them bend up the parts and possibly weld the notch to the frame box part, that way it will be square to itself.
you will get what you want, fabbed out of what you want. then just weld it into your frame. beware of welding too much at one time in one area though because it is easy to bend a frame with the heat/shrinking of the weld.
check out the web for ideas of how commercial suppliers have engineered their notches. no use re-engineering something just to say it's different.

[jweb]

Originally Posted by mobileortho

I like that , but it looks more like it's made for a 3100. There aren't a lot of options for the 3600.

Didn't notice you have a 3600.

You can use pipe or bend apiece for the notch and just use flat plate to box the inside of the rail.

If you don't have a way to bend the plate here are some premade bends you can buy:
https://welderseries.ecwid.com/Notches-c13377531

[dsraven]

you can also bend the sheet by marking it all out in sheet stock, then using a zip disc to cut slots where the bends will be, leaving a short connector every little bit to keep the parts together, then use some brute strength to bend the parts where the slots are. when done weld up the slots.

[mobileortho]

Looks like finding the u bolt mounting plate is next to impossible. I see them all day long for a 2.5" spring but nothing for a 2". Any suggestions on where to find one?

Never mind, found them.

[mobileortho]

I decided to weld them in from the back side. Still got to do a bit more welding but I think it's going to work out fine.

[MARTINSR]

Sorry wrong thread.

Brian