Did the factory 99T 239 engines have steel sleeves like the 221's? I am looking at one to buy but not sure if it has been bored too far and recieved 8 sleeves or is this factory. The center water jacket is round, while the bottom one is keystone and it has a factory relief. Also 2 oil fittings in the back with a pad for a third. No raised deck. I really don't want to shell out much for a block with 8 sleeves.
99 production was mixed, some with and some without sleeves...also true of 221. OEM sleeves are thin, I think .040, but look thicker at top because there is a small flange. For small overbores the gap at top where flange lives is high enough not to be a ring problem, for hotrod bores it disappears. The sleeves allow a rebuild with no machine work, or they can be removed and engine bored. 3 5/16 is generally very safe, 3 3/8 and 3 7/16 are done but getting riskier...but remember the 99's were the general choice for large displacement race motors. Description of passages sounds right. Are any of your parts marked Canadian?? The extra oil boss and relief sound wartime...and USA was not in war yet in '39-40. Does this block have 2 long vertical bulges on each side, with pan rail plugs at the bottom? That would be typical of '39-40.
I was not able to find any "C" markings or anything else that would make me think Canadian. However it does have two bulges in the block on each side where the block meets the pan. Thanks for your input!!
On the boring...sounds like you were thinking modern. These things are not like a 302 that gets tossed in the dumpster at .060...a 239 flathead bored out to the biggest rebuild type pistons offered is still generally smaller bore than the smallest rodded ones. 1/8 over is kind or hotrod standard, and many have survived race use at 3 3/8...some at 3 7/16. You need to worry about possible cracks, but anything that hasn't been in the hands of a hotrod hoodlum is unlikely to be bored too far.
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