1972 C10 Locking Gas Cap

[crustysarge]

I have tried two different caps and neither one works. AutoZone CST 5771 and Stant 11571. The Stant catalog lists 10571 but eveyone came up with 11571, interesting.

The Stant goes on but will not turn or seal. Seams like it needs to go down another 1/4" and I can push it to the gasket in the cap but it will not turn or stay down.

Anybody have a good locking vented cap P/N?

[badpeanut]

I have the Stant 10571 (at least that's what the catalog said) locking gas cap on mine. It seals and works well. Could you explain what you mean by it "...will not turn or seal"? To install this cap you line up the two fixed bosses with the two slots in the filler neck and the two retractable bosses at 90 degress from the fixed bosses momentarily deflect out of the way and then latch when the cap is pushed on (no turning).