Diffy-Vent $29.95 
+postage added at checkout
3/8-24 thread.
Fits 1928-1948 Ford rear ends.
INSTALL only in topmost right hand (passenger) side.
(standing at back of car looking forward)
Made of steel hardened to grade 8.
Sintered copper breather repels moisture and dirt and allows air pressure to
equalize differential interior pressure. Easily cleaned.
(Not suitable for underwater use)

To purchase large amounts please contact me
 [email protected]
513-724-9000