Ok engine now apart except heads, leaving that for machine shop. Balance shaft is indeed roller bearings at one end, looks like needle bearings, so just going to clean and oil them, not change anything.
Pistons have luittle wear on the, so unless tyhe cylinders have to be bored out, plan on reusing them. Anything I should know about regarding cleaning or inspecting them?
Main bearings showed a bit more wear than I expected, #4 showing copper, and crank journal has some minor grooves in it. Will see if it can be polished out or if it too will have to be ground. Also #4 main bearuing cap has a slot machined into the sides of it, and it looks like RTV was used to fill it as well as a slight bead between cap and block. GM manual briefly mentions a wedge type seal that goes in the slot, but nothing about any sealer than goes with it.
Trying to remove oil gallery plugs in block to clean everything. I see 2 welch plugs at the front near the camshaft, and 2 pipe plugs at the back in about the same area. I presume these are the main fore/aft oil galleries any tips on getting the small welch plugs out? There is also another pipe plug on side of block around area of oil filter bracket, is that part of the oil system? On reinstallation, are these plugs staked with a punch?.
Was on the fence hoping to be able to reuse camshaft, had a bit of wear on it, till the very last lobe, which had significant spalling on the lobe tip. Guess going to change it all out.
There is a bit of deposits on the pistons, primarily on the top. I read somewhere there is a coating on the pistons, which can be easily removed during cleaning. Would giving them a soak in varsol followed by a brief rub with a Scotch Brite pad be OK? Or just leave well enough alone?
Sorry for the many questions, thank you for all those who share their expeience on these engines.
Jeff