You'll most likely need a new tank pad. You can buy them online and there's also a user here that makes them. I forget who, I bought one from him and it seems to work well.
New grommet. Some don't fit right so be careful. Here's the one I purchased and it fit and works very well:
1967 - 1976 A Body MOPAR FUEL Grommet Gas Tank Seal CORRECT FIT New | eBay
Save your OEM lock ring, the one that comes with the new may or may not fit
Before you put the tank in the car install the sending unit. Look through the filler neck hole with a flashlight and make sure the pickup tube reaches all the way to the bottom of the tank. I'd also pour a gallon of something in there to check for leaks at the sending unit.
You may want to replace the straps at this time. Spectra makes those also
Check the J bolts and nuts of them for rust. You may want to start soaking those in penetrating lube days before you remove the tank.
