i was up on TWM's web site and that's the same stuff K&N use to sell
so either TWM used to make it for K&N or TWM bought the molds
I bought my adapter from Supeshops
a few small problems where
1) you could not use a base for the air cleaner
that would lift the air cleaner up to high
2) there was a little interference with the passenger side hood latch
also Bob hit the nail on the head, you could use the finned snorkel with the stock air cleaner set up
And put a K&N in the stock canister.
the cost was around $95 back in the day
one small problem with snorkel
it is shorter then the stock snorkel so it might not flow that well
i always wondered about that
i will try to take a PIC of the round adapter
Davegt74