To get you up to speed I've got an 02 Blazer 2dr 2wd AT 4.3 vortec with 175k miles. I dropped a lifter on the #3 cylinder, so I replaced the lifters today. The Haynes said to torque the rocker arms to 35ft lbs if it has the bolts (my model has bolts) or 20ft lbs if it has the nuts. When doing so right before the torque wrench was fixing to click at 35ft lbs I heard a snapping noise. I backed it off, took the rocker arm back out, and found a piece of the rocker arm support broke off the cylinder head clean in half.

I'm trying to avoid taking the cylinder head off. I did find the dealership part # for the rocker arm support itself. I'm hoping it won't cost me an arm and a leg, but I'm thinking it's going to be cheaper than buying re-manufactured heads. I'll find that out in the morning when the dealership opens. The support has a beveled edge on the bottom where it inserts into the cylinder head, so does anyone know how to remove it and replace it without removing the cylinder head? Is it as simple as prying it out, setting the new one in place, and torquing the rocker arm bolts down to it to seat it, or do I have another big job on my hands here?

Also can anyone verify that 35ft lbs is the correct number? This seemed kind of tight to me, but that's what they Haynes says.