620 & 521 Rear Bumper Interchangeable?

[Coach K]

Hey everyone, I'm looking at putting a hitch on my 521 and I found out that the bumbers from the 521 already have a place for a hitch to be put on them. My question is this. Does anyone know if the rear bumper from a 521 and 620 are the same or Interchangeable? Any help is greatly appreciated!

 

[datzenmike]

Usually the 521 had two piece chrome 'bumperettes'. The 620 had similar ones available but subtly different in the mounting brackets.  Many came here without bumpers installed that were bolted on at the dealers and  were the ugly heavy ones across the back. Frame spacings were similar so they may swap, don't know about bolt holes..

[Coach K]

I'm trying to put a trailer hitch on my truck and not finding anything that will fit it. Any Ideas?

[DanielC]

This is one style of rear bumper.

 

This is another.

 

There are four holes, two in each frame rail for bolts.  The stock bumperettes are bolted with 7/16-20 bolts, I do not know if they are grade 5, or 8.

 

As far as I know, 521 trucks had either the bumperettes, or nothing when they were shipped to the states.  Most of the heavy-duty bumpers were made custom in the USA.   The bumper bracket bolts on the outside of the frame rails.  it should not be that difficult to make some brackets, and weld a piece of steel across the brackets, or most any trailer hitch shop should be able to fabricate a receiver type hitch for a 521.  

[Rocket Dog]

My 72 521 came with this kind of bumper.  I replaced it with bumperettes but now went back to the original steel bumper (painted black).  My other 521 has a nice Bardon steel bumper.  I'd go with grade 8 bolts because, harder is better.

 

[84TAVeRT]

well I did some measuring for my project and an s10 frame is really close to the same width at the rear. less than .25" difference. you could probably use an s10 rear bumper with very little mods.

 

thanks,

Chris

[Sapoo]

What are the bolt sizes for the utility bumpers? Can't seem to find it.