Questions on the rear of the cab to frame measurement. I am setting up my rear mount positions and am figuring how high the back of the cab should be. With the cab perpendicular to the frame I have 1 1/4" from the frame to the pinchweld. The rocker panel looks to be in the same plane as the frame at this point but I have been told that the gap may be too much? Anyone have a measurement of this are or a measurement say of the running board to the front of the rocker and back of the rocker? I would think the running board and rocker panel should be parallel.

 

your thinking sounds good to me Dave... I was gonna way the lower window sill and the frame rail... that's about the flattest part on the cab... but the rocker panel is another good choice... your frame should provide the rake not the cab

later
John

 

Can anyone get this measurement or can get the bottom of the rocker to running board measurements?

 

I hesitate to use mine as a guide, but here's what I found. First off, the two pieces (outer shell and inner) don't align worth a darn along the flange, see pic. The PO was content to let the cab ride on the frame, so my flange is battered there. So I measured to the main part of the cab as shown. Very hard to put a ruler on it and read it, so that's as close as I can get.

BTW the pinchweld isn't flat across the frame, it's scalloped for clearance (even before it took a pounding).

 

Thanks, I agree the frame should set the rake.

Thanks Ross, I appreciate the time to get the measurement. I may be about 1/2" higher which isnt bad, I was concerned that I was 1" higher and I might have too large a gap from the back of the running board under the rocker panel. I will set the cab parallel to the running board and let it fall where it may.

 

As I read your ruler, I think you may be 5/8" or more higher than mine. But I think your approach is correct. Like I said, I hate to use mine as a guide, hopefully some others can confirm.

 

Might be 3/4", but it will work. The pads I have under the front of the cab may be thicker than stock, have to compare them.

 

Dave,
I just measured mine It is 1/2" +/- .060 from the top of the frame to the bottom of the pinch weld. Another way to say it is that the metal to metal gap is the above measurement . Restored original cab with totally original rear cab corners, original pressed steel "dog bones" with new rubber in all mounts. I did move the trans crossmember back over a foot however that should not have changed the frame width at the mounts

 

Thanks, sounds like I am good to go. I just went out to the shop and set the cab parallel to the running board mounts and am at 7/8" to the body line, same as Ross, and would be around 1/2" or so to the pinch weld as well. At this setting the back of the cab is not perfectly perpendicular to the frame rail but it looks like it isnt supposed to be, bad assumption. I wont be able to get to make the mounts until Monday, but I will set them up with the cab as it is now.

 

I leveled the frame, then leveled the cab measured at the floor. I can't tell you in inches but I used a 1'x6' board as a spacer. looked about 5/8 inch from the lowest part (sitting on the board) to the top of the frame. I used adjustable mounts sold by mid-fifty to permanently get that height.

After leveling the cab you should set the running boards to match cab, not the other way around imho.

 

Running board mounts are fixed in a straight line to the frame, so they should be a good reference point as far as the plane of the frame rails. Setting the rocker to them will keep the cab in the same line, side pictures of finished trucks look like the bottom of the rocker is parallel to the running boards. I will be double checking everything before making the mounts but I would rather be a little low in case I need shims. Hard to go back if I set it too high.
1" finished board should be nominal 3/4".

 

Mine is 1 1/8 from the bottom of the cab to the frame and 4 3/8 from the bottom of the rocker to the running board.