M51A2 dump bed install questions

[eric67camino]

When i got my truck (1952 Mack M51A2) the bed had been removed by the fire department that had it so that a tank could be installed. I have since gotten a correct bed and have been working on getting it installed on the truck.

While attempting to install the taillights to the correct location today, I think I found some issues that maybe someone knows the solution to.

1.) When bolted in place the wires don't line up with the hole in the crossmember and would instead be pinching them under the housing.

2.) I have the bed subframe blocked up for right now, but it appears that the taillight housing will hit the main frame crossmember when lowered into place.

3.) The rear of the subframe has a plate with hole to sit around the rear crossmember bolts. This will sit the subframe up a little in the rear.

It seems like I have read about the beds using a wood spacer/shim between them and the frame. I assume that would fix that part, but I am wondering about the taillights. Is there a different taillight housing for the dump trucks? Or do I just need to drill new holes. I didn't want to drill if it could be avoided. I'm not doing a 100 point restoration, but I am trying to keep it as "correct" as possible.

 

[Evil Dr. Porkchop]

Early trucks had small round taillights with a cats eye lens, the wires will be in a different spot than the new larger taillights used since around 1970ish. On my 2.5 ton dump truck the mounting holes are drilled lower and the composite lights work then, maybe you could do the same on the 5 ton.

There should be a wood spacer between the bed and frame with holes for all the rivets that stick up.

 

[eric67camino]

That's what I figured. How do the later trucks use the larger taillights? Are the the mounting holes just drilled higher so that the wires line up?

 

[wanderingwillys]

The easy way to tell is compare the bolt holes for mounting the tail lamp to where the clearance hole for the wire is - if they are almost all in line it's an early round tail lamp if the wire hole is a fair bit below the center line of the bolt holes it is for the later teardrop tail lamps...

My dump bed has both styles of holes on the back panel...

 

[eric67camino]

Looks like it's just got the older bolt pattern. I guess I'll have to drill for the newer pattern.