Sending unit is loose in the gas tank

[midnightrider78]

I just replaced the gas tank in my '72 C20. The new tank is a Spectra. It fit surprisingly well(had to tweak the neck just a little but I'm told that's just how they are). The sending unit is virtually new(replaced a couple hundred miles ago).
My problem is, when I install my nearly new sending unit(with new o ring) in my new tank, it is still loose even after the lock ring is in place. It fit just right for the short time it was in the old tank.
What gives?
Is there anything I can do other than hopefully finding a fatter o-ring?

[Boog]

That's a good question for Spectra.

[Boog]

That's a good question for Spectra since it fit fine in the old tank but not theirs. It could be you have to buy a sending unit from Spectra to match their tank.

[LockDoc]

Originally Posted by Boog

That's a good question for Spectra since it fit fine in the old tank but not theirs. It could be you have to buy a sending unit from Spectra to match their tank.

Or at least an "O" ring from them.....

LockDoc

[midnightrider78]

Originally Posted by Boog

That's a good question for Spectra since it fit fine in the old tank but not theirs. It could be you have to buy a sending unit from Spectra to match their tank.

Hadn't thought about it, but I suppose it's a possibility. I'm so sick of being forced to use repop parts that are all from the same manufacturers because they insist on making them "sort of similar" to the originals instead of exact reproductions(even though many companies use that very phrase to describe their parts. HA!). Hopefully I can just dig up a fatter o-ring. I refuse to buy a new sending unit(again) just because of the poor quality of aftermarket parts.