According to Four Seasons the only other possibility is a part number 83175.
It has a .395 ID with 16mm fittings.

But it is aluminum and I am concerned it might not seal properly because the old one had .330 ID

'88 Dodge Raider with only 52,000 miles!
My upgrades:
Curt 2" receiver tow hitch
Re-undercoated the wheel wells
Gen 2 padded center console cover "armrest"
Highland all-weather front mats
Double DIN JVC Receiver
Power locks with remote