well i lucked out with a parts truck i bought and it had a good front sender and foot but it had a narrow frame so the rear was different. so i will have to rig a foot to the old nonworking rear sender or buy a gas rig sender then rig a foot for the rear.
and the foot length is 3 1/2'' a 1/2'' slides on the tube so ya have 3'' sticking down. the fronts foot is the same as the rear i am sure to also. as the pieces i could see in the rear tank was the same sizes.
maybe this will help some others in the future as there very light help on the net it looks like on this problem.