Well it cooling system was having a hard time keeping up so it all came off, but before hand I bought a high volume pump, aluminum radiator, and took it all apart. During disassembly I found the thermostat bypass tube at the thermostat filled with silicone, half the old thermostat blocked by silicone, and the block coolant passages from the water pump half closed off with silicone.
So it is safe to say the previous owner loved applying way too much silicone. But since I had the new parts I went to install them and found the lower drivers side bolt for the block inlet port wouldn't tighten up. D*mn stripped bolt hole. So off comes the timing cover to helicoil or step up to a 3/8 bolt from a 5/16.
What did I find? The bolt had at one time been way over tightened or something had caused the area there to crack all the way through the wall between the coolant passage and the timing chain area. It was smothered in......SILICO NE! After getting it all cleaned up it was clear that the chunk of block could come loose and fall in to the timing gear drive, it was still attached but clearly a problem, the chunk was about 2/3 the size of a golf ball.
Well what to do? New block, take it apart and re-use the parts? Another engine?
NAW, I remembered I had one stick of Certanium 707 from years ago. (Used it for welding Hastelloy C276 and 316 Stainless together) Took the grinder and notched it after knocking off the Arc welding flux on the rod, and used my TIG to weld it up after pre-heating the block as much as I could. Used a grinding disc to smooth it down as best as I could, used a carbide 4 flute angled chamfer bit in a drill to flare the bolt hole and took a little longer bolt, turned the head off and tapped it in the hole and welded around the bolt in the chamfer to make it a stud now.
The thought is if the piece cracks or breaks off there will be leak but the chunk won't end up the timing gear drive as it will be attached to the stud. The weld should hold as it only holds the timing cover and water pump on, it ain't pretty, but now I get to silicone up that area.
I didn't have any proper cast iron rod but have used Certanium 707 in the past on cast iron and never had problem, and the area will heat and cool uniformly with rest of the block, and isn't exposed to cool air like a manifold would be. Guess this winters project is a to build another engine.
Will post some pics after it is all together, my welding sucks on this repair and I ain't showing it off.