Good ol'GM V-6s with bad intake gaskets. Happens on them all, 60 degree or 90 degree. My first toy car was a 1993 Lumina Z-34 with the 3.4L DOHC. Even before I turbocharged it, it would eat intake gaskets. Over 4 years of ownership, I put 4 intake sets in it. Turned out that the manifold had warped. Got a whole intake manifold set on the last set of gaskets, and that set lasted til I blew it up, about a year and a half.
Gotta love it.
Gotta love it.