Rear fuel tank install Q

Can you guys see the above pic??

On my 4WD rear gas tank ('70-'75 15-gallon), the seam in the middle is the problem. During the installation, the 2 rear-most corners of the middle seam are at 90* angles and bind against the rear frame rails and shackle bolt heads. You might be able to see the "corner" of the rear seam in the pic behind the auxillary fill neck.

Sooo, using a bench grinder, I ground down the rear corners a smidge to clear the frame so the tank could be mounted level. Here's the concern.....One time I ground down an underseat tank's seam by 1/4" and gas slooshed out of it later. Will the same thing happen to this rear tank? Unlike the underseat dealio, the rear tank has an apparent "stamp" that binds the seam together all around, and that has not been violated with my latest fab effort (that "stamp" all around is visible in the pic as a dark line all around the tank). Anyone dealt with this b4?

 

It's a new tank. Yes it could be soldered/brazed, but I would only do that if for sure gas slplooshage is inevitable. Perhaps it isn't?
Mike: I didn't grind much, and certainly not past that thing that looks to be the seal stamp all around. Also, the entire rear seam isn't soldered together (you can see the 2 halves' edges), so that "stamp" must be the inner seal??

 

How about some gentle persausion to fold the lip up or down a mfh ?

 

I just finished the same install on my 75. I ground the corners down, but only a 1/2 inch, once I got it slide into the grooves near the rear bumper, I was unable to use the original stoppers, so I built a plate mount to hold the tank up and put new bolts in the original holes. Hope this helps

 

Yes that helps much, thanks for posting! ! ! I did grind a bit on mine just to clear the tapered frame. Haven't tested it yet tho.