putting a '72 & older rear bumper on a 1977 stepside

[77 longstep]

I got the pictured bumper for a good price.  The guy said it was pre 72 stepside and I want to put it on my 77 longbox stepside. 

The outside frame supports are 34 5/8 inches apart and the frame on the truck, outside frame, is 34 1/8 inches.  I'm thinking of spacers or plate steel to fill the gaps and the holes don't look like they match right up.  It looks easier to drill on the truck frame than this bumper support.  This thing is heavy duty.  Still gotta figure out the license plate since the new bumper will rest right below the tail lights, so I'll need a plate bracket.

I figure that someone must have done this before and I thank all in advacne for any light they could shed on this.

Greg

[bake74]

     I do believe the overall distance from end to end will be shorter than your 77.  Have you measured to see it will fill from edge to edge yet ?

[77 longstep]

I just taped measured it and the truck frame.  We held it up there and it looks like a good fit.  Somehow or another I'm gonna put that thing to use.  Right now there is a fleetside bumper on it and some idiot ran his hondacar into it while the truck was parked.  Sent the idiot back to the village that was missing him.

I'll post a current pic and you'll see why this heavy unit is gonna fit.

[77 longstep]

I'm not getting any input in the body section about this.  I'll try it here witout adding the pics and just link to my post in the body section.  I'm a Pontiac guy and am used to the board over at Performance Years.  I'm not used to the slower pace over here yet.  Maybe my topic is lame and maybe I put it in the wrong place, we'll get it to fit somehow.  I just thought someone may have done this before.  This is for a stepside truck, the bumper on there now is for a fleetside and some idiot ran into me, while parked.
Thanks in advance,
Greg

http://forum.73-87chevytrucks.com/smforum/index.php?topic=28544.0

[bake74]

     You most likely have not gotten any responses because you asked if anyone has done this before, nobody that has looked at your thread has done it most likely.

[77 longstep]

Thanks for the reply. 

Not a popular switch I guess but I fell into this bumper and it is quite nice.  If we get it to fit I could get it wrikle powdered or chromed.  Nothing to lose since the fleetside one on there now looks like crap and has been crashed.  I could hook a log chain on and find a tree, but I'd still have the wrong bumper on the truck.

Take care,
Greg

[Captkaos]

I wouldn't consider this a switch since you aren't talking about a factory piece, this would be more along the lines of custom, as in it wasn't made for this and you want to make it fit.
I am not sure what direction you have as far as issues go, but if it isn't wide enough to fit inside the framerail just shim it out.  There are already holes in the frame so make sure you don't drill any new ones too close and weaken it.

Side note:The Stepside factory bumper is the same from 1967-87.  Only the mounting brackets were different.