New instrumentation for my 81

Pete - The sending units go in as shown below, although I can get an actual picture later today if you need it.

9002 = fuel tank
9276 = gasket
9A307 = lock ring
9H307 = sending unit/pump

The lock ring is tightened with a brass drift so it doesn't give off sparks.

Thanks Gary. Yeah I kind of figured it might be a lock ring arrangement instead of a bolt in. My buddy's early Mustang has a similar setup. Some modifications to the sender will be neccesary I'm sure. I have some ideas on how it might be done, but I'll have to get the tank down to see what's what.

I took the tank down over the weekend to see what I was working with. Tank and sender were pretty new, but the pickup on the sender only extended about 8 inches into the tank, while the floor of the tank was a good 10 inches away. Pretty sure this thing would have run out of fuel with 5 gallons left.

There was no sock on the pickup tube either, I don't know if they are typically used on this truck, but I think they're a good idea so I ordered a GM one that fits a 5/16" tube, which is what I have. I also straightened out the bends on the pickup so it comes very close to the bottom of the tank.

The fuel sender that works with the VDO gauge had no provision for a pickup in it, nor would it have interfaced with the locking ring without modification. So I ditched the top of it and modified the Ford parts instead. The construction of the TAN VDO sender was pretty modular, which helped a lot. I disconnected the top ring from the adjustable "ladder bar" that held the sender unit itself. Just had to unscrew the 2 nuts at the top center of the thing.



Then I took the sender connections out of the Ford top by drilling out the rivets. This left 2 small holes, one for the ground side and one for the sender side. I drilled one of these out to the same size as the center hole in the TAN VDO sender, which was 25/64".



The remaining hole was then too close to the sender to be of any use, so I welded it up. Then the TAN VDO senders ladder bar could be installed on the Ford top. I also tied the ladder bar into the Ford part with a small screw, so it could not rotate and was positively grounded.



Then I tack welded a 6-32 screw to the top to provide the ground side. When it was all assembled it looked like this.



With a little squeezing and prodding, it will fit back into the tank. But before I put everything back together, I need to get that pickup sock in the mail, and I also ordered some parts to replace the filler neck hose, since the one in there was looking pretty crusty. I did verify that the sender ohm range is proper, so all my messing with it didn't hurt it. Should work fine once it's back together, and if I need to replace the sender again for some reason, it's a bolt in thing at this point.

Quite innovative. Good work!

Well done!

Yes, good job!  

A Ford fuel sender that actually works?

Shocking!  😄