So my 1990 Laser w/ 5-speed Tranny makes a noise exactly like a supercharger. This happens mostly under high load in 3rd and 4th.

It's unbelievably cool to hear the engine, turbo, and "supercharger" all spooling up at once... but it can't be a good thing.

Only known issues I can think of are 150k miles on the tranny, worn throwout fork & ball, or tranny -> block misalignment. (The long 12mm bolt directly above the driver output shaft is missing, causing a 2mm gap between the bellhousing and block.) The first explanation is the only one that makes sense to me.

Is this a common thing on higher milage trannys? I'm dropping the tranny in the next week, fixing the bolt and fork. What else should I check out?