Got it out and apart...
Not near as bad as I feared. Blown head gasket on front(left) head on center cylnder. It had already been replaced with a Felpro gasket at 95,000 miles because they had it apart to replace the crank and one rod. I have no idea why that had to be done, othe rthan it was just broke It now has 157,000. IT has had the smaller pulley the last 10,000 miles. The front(left) exhaust manifold is cracked big time and a new GM one has already been ordered. I have also replaced the harmonic balancer with a Napa one and it has cracked and slipped on the crank no less than 90 degrees. It looks like it jumped out of the keyway and traveled about 90 degrees until I took it apart. I did not replace the key when I replaced the balancer. It looked like a bitch to take out. It was easier after the motor was out and the timing cover was off!
Now that it is apart and we know what is wrong, do you have any suggestions on ANYTHING going forward? Especially brand of head gasket that you have used?