47-55.1 Rear Cab Mounting

[fauXGT]

Working on the Rusto-Mod, and with all the different parts from different trucks, I can't find the info I'm looking for.
It's a 3100 frame in almost perfect condition. The cab is from an old farm truck. A 6400. The cab had a few minor rust issues, like most, but the rear cab mounts were in great condition. They don't line up. 3100 frame has offset holes to the frame and the cab shackle mounts are straight up and down.
All the info I get from searching is 3100/3600 frame to 3100/3600 swing mount measurements as far as length from bottom of shackle to bottom of frame. With equal space on the rear of the cab as it wraps around the frame, (1.5") from above and sides to the frame, it gives it a slight rake. .6" higher at the rear of the cab compared to the front to the running boards.
Does the cab run parallel to the running boards or does it rake a bit like a hotrod?

Any help is appreciated.
Chip

[mr48chev]

You actually pretty well answered your own question and until a few months ago I didn't have the answer.

3100 holes are offset, according to this 3600 and larger holes are one above the other. I couldn't be positive of that on 3600 trucks to save my soul though.


Cab lines, Bed rail and running boards should be parallel. One of my gripes and especially with the S-10 frame brigade is drooping the back of the bed down like it is a diaper full of ____ in their misguided idea that it makes the back of the truck look lower.

The info on how to set the cab the right distance off the frame is here in my photobucket album
Scroll down the page to 05 May 2012
https://photobucket.com/u/mr48chev/a...c-87a31c3a5b15

12 May 2012 has how to adust the hood.

[fauXGT]

Hard to read from Photobucket being it zoomed in and pulled out while trying to view(kinda like trying to watch a bad horror movie).
It looks like .75" from top of frame to lowest part of cab. I'll have to look at measurements tomorrow to see if that'll square up the cab to the running board.
Thanks for the info.

[fauXGT]

I can see the cab to running board being parallel, but it's tough to see the frame into the equation when they widen and rise and fall over axles and such.

[joedoh]

I prototyped this part a few weeks ago.

[mr48chev]

I'm thinking of doing something similar on the 48 with the extended cab.

[fauXGT]

I guess one of the things that threw me off was how close to the lower frame the bottom of the shackle was hitting. Barely enough room on the inside of the frame for a socket to fit. It works though. Thanks for the info.

[fauXGT]

Originally Posted by joedoh

I prototyped this part a few weeks ago.

So is this for a modern straight up/down body bushing instead of the shackle?

[joedoh]

yes, the original shackle doesnt have any adjustment, and as the bushings wear the rear of the cab sags.