I think it was 14 gage also, but I'll have to measure it when I get home. I know the pipe and plates were a few thousandths thicker than the original metal. The same OD, but slightly smaller ID.
Truly, the most time consuming part of the job was removing the old pipes from the frame. I cut them off flush using a body grinder with a thin cutting blade. There are 3 welds on each outrigger tube. I then used a carbide bur on a cheap air powered die grinder to work around the inside of the tubes until they loosened and could be punched out of the frame. One or two got buggard, so I had to used tin snips to reach in and cut the inside till it could be pulled out in a spiral strip.
It sounds complicated. It isn't, but it does take a while.
Oh...almost forgot. The measurements for the outriggers are given in the service manual. You must do one rigger at a time and match it to the manual measurements at the mounting pad. I say this as the frames have slight variances along the tubes, but the outrigger mounting pads are usually spot on. If you take measurements from the frame tubes, each rigger will measure 1/8" or so different from the rigger on the opposit side.
It takes a while, but it's a feeling of accomplishment when you look at that pretty fresh outrigger when you're done.