1966 GMC Rear Bumper Installation Issues

[BFoley]

I am finally Getting around to finally install a repro bumper and cannot for the life of me find any good pics/resources on the placement. The truck has several bolt holes (two 1/2" and one 1 1/4") on the frame rails that were used to attached an incredibly stout one-off bumper that I removed this past summer. I purchased the bumper and brackets from LMC and nothing seems to match up.

I have scoured the internet trying to find good pictures of bracket placement but am coming up empty-handed. Whether adding a bumper to a truck without one now or back in '66, were holes required to be drilled? If not, can anyone look at my pictures and let me know what is up? Also, if anyone can snap some pics of their installed brackets, I would be beyond grateful.








Thanks,
Ben

[chevy49]

if I remember correctly you use the large hole and the small one the bracket is at an angle.

[DPowers]

Does this help?

[Slow Build]

Hope this helps.

[BFoley]

Originally Posted by DPowers

Does this help?

To me, it looks like there are a few issues with my frame. I believe my truck is numbers matching, but the differences in characteristics on supplied pics is concerning me. The attachment holes on yours and other pics supplied look different from mine. Your larger hole is toward the top of the frame and mine is toward bottom. Mine doesn't have slotted/elongated holes. Your mounting holes are not on "same plane" and both of mine, on each frame rail, run parallel to rail (there is one covered in my picture by inner-frame bracket).


I greatly appreciate the pic though. Hopefully I can get this figure out.

Thanks,

Ben

[BFoley]

Originally Posted by DPowers

Does this help?

Any chance you could provide me hole locations from rear of frame? I am going to design some brackets of my own.

[PGSigns]

Can we get some more info about your truck? Maybe some pics? May help figure it out. Almost looks like your frame may have been shortened.
Jimmy

[BFoley]

Originally Posted by PGSigns

Can we get some more info about your truck? Maybe some pics? May help figure it out. Almost looks like your frame may have been shortened.
Jimmy

I will take some pics today or tomorrow. My truck is actually a LWB.

[BFoley]

I am also wondering if there would be any difference in the 3/4 ton and 1/2 ton frames? Mine is 3/4, not sure what the pics provided are?

[TJ's Chevy]

If yours had the telescoping rear bumper that had provisions for a ball on the bumper then the frame will Not have the same mounting holes. I have yet to see a stock 3/4 ton with the repro fleetside rear bumper actually. lol

[cru_zn_29]

I/2 and 3/4 frames are the same for chevy. looks like your 3/4 4x4 GMC is made different i don't see the rear cross member.

[BFoley]

Additional pictures taken and put in album to retain large image size. For now, I am trying to figure out if frame is correct. Was led to believe it was a numbers matching vehicle and everything about truck would lead me to believe it is but VIN isn't present on frame where online resources say it should be.

http://imgur.com/a/xpkfs

[Slow Build]

The VIN should be a little farther forward. Mine is forward of the motor mounts close to the power steering pump.

[Classic v6 GMC's]

US built GMC trucks did not have the VIN on the frame. Our 66 gmc 3/4 4x4 does not have the holes in the frame either so my guess is that no 3/4 ton 4x4 trucks came with factory holes in the frame.

[BFoley]

Originally Posted by Classic v6 GMC's

US built GMC trucks did not have the VIN on the frame. Our 66 gmc 3/4 4x4 does not have the holes in the frame either so my guess is that no 3/4 ton 4x4 trucks came with factory holes in the frame.

I read that a few times on sites last night. I am glad I cut off the huge plates that attached the one-off bumper to the frame. Since I want to incorporate the receiver/pintle hook back back onto the truck, it is looking like I am going to have to fab my own rear bumper brackets or modify the LMC ones.

Thanks to all for the help!