[richtazz]

When GM redesigned/refined the 3100, and switched to the roller rocker arm design, is when the trouble started. The redesigned intake coupled with the rediculously low torque values allowed the bolts to loosen over time due to the different expansion rates of the metals invloved. This allowed the intake to "walk" side to side and eventually cracks the plastic body of the junk OEM gasket at the coolant transfer passage allowing coolant to get in the oil. The newer design metal-rubber laminate gasket and the use of threadlock on all the intake bolts will eliminate this issue. I've done many of these intake jobs, and on almost every one, the end bolts (the 4 short ones) were barely finger tight (some I could remove by hand). The actual issue is a combination of a junk gasket design, and no use of threadlock from the factory to keep the bolts from gradually working their way loose. You will rarely if ever find this issue on a ball and socket rocker arm 3100 or VIN-T 93-older 3.1, even though the basic engine design is the same.