Most of us run vent lines to avoid the oem vent getting stuck in the open/closed position, more of a problem if closed since the air pressure build-up caused by heat can't escape through the vent so it finds the next weakest point, i.e., the axle seals. You can do it for under $20, depending on how much hose line and new fittings cost you.

More than tread lightly. Leave it like you were never there, nor anyone else.
'90 X-cab 4.88's 33 BFG AT's, rr ARB, Headers, Ignition upgrade, cold air induction.
'91 X-cab 5.29's 315's BFG MT's, rr ARB, custom bumper and flatbed