I realize you want a stock outlet. A ball valve would be nice.
Commentary:
If I had that type of tank I would plug the bottom outlet with a pipe plug and find a top pickup/sender that I could modify by copying the configuration of the old sender. The round mounting flanges and the 5 holes are standardized, albeit "keyed".
The bottom outlet and the valves have too many leaks and seem to have clogging issues from what I read.
I have played around with pickup tube senders making a TF truck sender into a suburban sender.
You can bend/cut/modify the float arm and you can bend/cut/modify the pickup tube. I have even modified the rheostat. All to make a new/different sender that, at the time, was not available.
Showme: If 54 has pick up tube senders and the gas tanks are the same as 51, it seems like a direct swap to add a tube sender. Don't see any issue with changing except a little replumb/rewire. The PO's 46 would require some investigation but he wants that area to stay stock for some reason. That means he can't have a ball valve, larger rear view mirrors, no seat belts, no radial tires, no turn signals and shouldn't park inside a garage near a water heater.
(just kidding David)
