all 22re's have the same vent on them also. i think its for the pcv valve. im not sure. i usually grab them off motors at the junkyard if i see them.

87 22R PU, 2? body lift, 33? BFG muds, 4.88's, F&R Lock-Rights, Rancho Shocks, EB's Street RV Head w/ 268 Cam, LCE Header, 2" to 2 1/4" exhaust, Flowmaster 50 series, Magnaflow high flow cat, complete Herculined SR5 interior, V6 BB, MC, and calipers.