Alrighty, somebody asked about how I fitted the bumpers to my car so here it is (sorry can't find some of the pics). I had to replace the whole rear of the car and the rear valence wasn't exactly of good quality so the dimensions I'm sure will vary on the height of the bumper. First off I started by measuring how much I needed to move it in, I cut roughly 1/2" out of the bumper brackets but would only tack it and then test fit until I was happy.
Next I chopped roughly 1/2" out of each side to move them into the pockets in the quarters for a flush fit.
There was a pretty big gap at the top of the bumpers on both sides so I added 3/4" to the tops as well and then heated the rolled lips up red hot and hammered them out flat which took up what was left of the gap around the bumper and the quarter pocket. The height was next (which may very), My bumper had a large gap under it so I used a junk bumper and took 5/8" off the bottom and grafted it onto mine to close that gap. Last was welding the brackets on and welding all of the bolt holes shut. 
All joints were V'd out so they could be ground smooth and the welds on the inside were left alone for strength.
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The fronts are really easy, elongate the slotted mounting holes 1/2" and they fit nice and tight to the front. I then took 1/2" out of each side like the rears and that takes care of the bumpers sticking out. I think I might have heated the rolled lips up on them to and hammered them as well but can't remember for sure.
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Hope this helps, if you have any questions feel free to ask.
Next I chopped roughly 1/2" out of each side to move them into the pockets in the quarters for a flush fit. There was a pretty big gap at the top of the bumpers on both sides so I added 3/4" to the tops as well and then heated the rolled lips up red hot and hammered them out flat which took up what was left of the gap around the bumper and the quarter pocket. The height was next (which may very), My bumper had a large gap under it so I used a junk bumper and took 5/8" off the bottom and grafted it onto mine to close that gap. Last was welding the brackets on and welding all of the bolt holes shut. All joints were V'd out so they could be ground smooth and the welds on the inside were left alone for strength.- - - Updated - - -
The fronts are really easy, elongate the slotted mounting holes 1/2" and they fit nice and tight to the front. I then took 1/2" out of each side like the rears and that takes care of the bumpers sticking out. I think I might have heated the rolled lips up on them to and hammered them as well but can't remember for sure.
- - - Updated - - -
Hope this helps, if you have any questions feel free to ask.
