Front bumper mounting issue

[Sinisterspeed]

Ok, i am finially trying to put the finishing parts on my truck. Here is the list of the issues that may be contributing to this problem.

Rear 2/3 of frame is from 71 GMC longhorn.
Front Frame horns from unknown year 4x4
Fenders are aftermarket
Core Support is from 71 GMC 2wd
Cab is 2wd 70 GMC
Hood aftermarket
frame has been welded smooth on the outside so no hole for outside bumper brackets. (Planning on drilling where ever it lines up to 4x4 brackts when i get some)

to do all the panel alignment the right front core support body mount was shimmed aprox 1/2 - 5/8"

now.. I have the inner bumper brackets from a parts truck i have here at the house. I tumbled and painted them. Mounted them to the upper holes of the new bumper.

The Issue.. Right side is almost covering the turn signal. left side about half of it. but all the brackets line up..

The obvious fix is cut the frame horns plate a flat edge and then move the bumper till it lines up with the body correctly and mount the frame horns back on to the plate welded to the frame.... Before I do this. I would rather "ask the pro's" is there something i am missing?

[Sinisterspeed]

Just went out and took a bunch of pics of the issue. I would REALLY not like to cut the powder coated frame if I dont need to. But this ain't gunna work like this.

[Sinisterspeed]

[Sammy]

I am no expert. But have seen a few with this problem. And it is more common with 4WD. And the 2WD I suspect had been wrecked on the R/F at one time. The 4wd trucks are probally from twisting in the frame. It doesn't take much to show up. And the only options to try is shimming the core support and shimming bumper brackets then last resort modding your frame horns. I think you could custom shim some bumper brackets with some serious thinking and the best place to start. Both L/R sides are too high.

[vectorit]

The outer bumper brackets are specific to 4x4 and 2x4.


Now a days you can get 4x4 outer brackets...

[vectorit]

Here is a pic of a 4x4 front bumper bracket on my burb, and it should give an idea as to whats up with your issue.

[Sinisterspeed]

Cool thanks guys. I think i got an idea on how to fix this.

I have another bumper laying around. Im going to cut strips 2" wide right where the inner bumper mounts are. Lay it inside the frame bolt the new bumper to those and weld a flat plate that can be bolted to the the frame to those. Thus loosing the stock upper mtg brackets to gain the room needed to align it properly... I'll post a couple pics once i get it mocked up. Thanks for your input..

I do still need to get some outer brackets and find out what kind of issue this is going to make for those. Maybe ill just make some.

[GruntMoanCough]

Is it just me, or are you trying to fit a Chevy bumper on a GMC? (They are different at the turn signal area.) Also, those frame horns look totally wrong to me and are causing the bumper to sit too high.
With the rad support shimmed up, you won't be able to get the bumper to line up to the grille. If the frame horns are sitting right, then maybe check to make sure the cab is sitting level to the frame.