Aaron Coolidge wrote:

In the past, someone made locking gas caps for the Cherokee tanks,
but they
are long out of business.

I don't recall an STC or PMA for Cherokee locking gas caps, but Piper
did and currently does sell these. Probably not very many though.
Last time I checked they were better than $700 each.

I always thought these caps would be a great opportunity for a 3rd
party PMA or STC. Lots of owners seem to want them, but no one in
their right mind is going to pony up $1,400+ for a set of locking gas
caps.

John Galban=====N4BQ (PA28-180)