Hey there Alvin, Just thinking out loud here.
1. Using your existing sending unit would be nice IF they are still available for when it goes bad. If they are not available it may change the approach.
2. It seems like your plan has too many bad problems. It seems like you should use a tank that has the 5 screw flange that is flat mounted, not 45 deg. Gives you a chance to find/modify a sender.
3. I have modified a sender for my suburbans/panels like Mike. Swapped out arms, bent arms, reposition the rheostat box, etc. Lot of work.
4. New tanks will be safe to weld on if some idea hits you there.
Like make a new sender hole (with a spacer for depth if necessary) or any other mod.
5. I would keep searching and also wait for other responses from early Chevy folks.
6. Can
This work? With the stock sender or aftermarket one listed by them? (click on sender and see all the ohmages) What are the issues with this mounting in rear? If I know the problems with this type, I can possibly find one that solves the issue or know better what your ideas are.
7. Don't ever throw away your old sender if it goes bad, you need it to copy.
