Bad regulator... Been fine on short trips but first 150+ mi has the battery venting

First long trip in a while (usually the S10 is a to-and-from work commuter), popped the hood when i got back home, battery was spitting some acid out and giving off that ripe smell. Surface temp on the front of the battery was 200f. Pretty sure my alt regulator has gone bad. I've got a new one on the way, but im gonna try to pull apart my current one and clean the contacts and see if that does the trick before it gets here. This is my only vehicle sadly.

On a side note, what's the advantage of running an AGM battery vs a lead acid in these older rigs... im the 2nd or 3rd owner, not really too sure but its had an AGM battery since i've owned it.

pulling the alt tomorrow and cleaning the contacts/bench testing the regulator to see if its bad.

1986, 2.8L engine (LL2), 5 speed trans (ML3), with a TBI unit. i'll post back after i "rebuild" the alternator/if it works.