I discovered today that the new stock replacement gas tank I bought is not going to clear the rear end in my car due to moving the rear end back for tire clearance. I don't really want to hammer on the tank so I was wondering if anyone here has ever notched out a tank in order to make some room between the rear end and the tank? Also, if feasible, I would like to narrow the tank width-wise on one side (the other side is good) to gain some room for a tail pipe. We were thinking of cutting the side of the tank off about an inch or two in from the lip, then cutting out a 3" section of the tank and then welding the side back on to the tank. Again, has anyone here done anything like this?

Sure it can be done but it sounds like you might be better off having a tank built ?

All things are possible when it comes to cars, especially with a new gas tank I went through something similar on my 1969 Dart GTS, I had the leaf springs moved into the rear subframes (before I knew it was a GTS and not a GT like the badges said ) and had to dent in the passenger side of the stock gas tank to clear the right side leaf spring. I was racing it then with no exhaust system, I sold the car and later bought it back. I have started to putting it back to semi stock, I bought a 3 inch dual exhaust kit from Summit, we ended up mounting the mufflers between the outside of the rear subframes and the 1/4 panels behind the rear end instead of putting them in the stock location That ends up making a lot less exhaust noise in the car with those type mufflers You might want to deepen the tank while your at it to increase the capcity

Sure have, here are some pics of a modified tank.

Running a triangulated four link, needed to have the shocks clear.

This is a friends car, lending a hand on the project. 71 Demon.

Back from the powdercoater, tank is 60% gloss, straps 95%.

Yes we did it..But sorry don't have pictures..all I did was to install another fuel pickup in the tank..the stock pick up goes to the stock type mech fuel pump the other goes to an electric fuel boost pump ..both lines go to a large fuel filter with 2 intake lines and 1 line going out to the pressure regulator..