Chad 2001:
I had the same problem with mine - cracked rocker shaft at the bolt hole on #8. Was backfiring into the intake. Turns out almost half of my pushrods were bent too, on both sides of the motor. I suggest pulling off both valve covers and checking for proper appearance and function because the noise seemed to be coming from the opposite side! And when you torque down the rocker shafts, do it carefully and evenly so you don't stress the shaft. Motor runs great now.
88 Subn 6.2 NA \'J\' 4X4 3/4 ton 155KMi <BR>Obnoxious pre-occupied tailgating commuting drivers holding cellphones seem to understand swirling black smoke signals without difficulty.