Hi Fellas   Trying to save this std bore 312. Bought this and 4 or 5 others in early 80s. Was looking for a std bore 312 for my 56 TB. Most of them were freeze broke. Finally found one with wrist pin gouge that I used. I saved this one, has a dent in deck (web area) where push rod go thru, 4 missing caps and number 2 main threads stripped. I check for cracks when I took it out of hot tank. Any body have opinion for thread fix or just let it go. Bill  Oregon