Satellite tank is a rear fill and there’s really no good way to route that fill location on an A body.
The B-body tanks are also longer, you have to cut and kick out the rear crossmember to do it. I run a Charger tank in my duster, it retained the quarter panel fill location. But yeah, I had to kick out the rear crossmember, fabricate new J bolt mounting locations, and extend the gas tank mounting straps to do it.
It gets you a 19 gallon tank that’s actually narrower, so it frees up some room for the tail pipes. But yeah, you have to get rid of the spare tire well, kick out the rear crossmember, and make everything you need to mount the tank. The filler neck is close enough to use the same hole in the trunk floor and makes it to the factory quarter panel fill location, but it’s far enough off that the rubber boot doesn’t work very well.