I have an 85 trans am 305 tpi and it has an aftermarket muffler. the tube that extends from the emissions system valve (thing the air pump connects to on the left side of the front of the engine) is still in place, but is welded shut near the new muffler. should this tube be un-blocked? i ran the car both ways and did not notice a difference at idle.

also, would overfilling the gear lube in the rear end cause it to leak out the seals at the end of the axle tubes? The car had a bent drive shaft, I had it re-tubed and the pinion bearings replaced.