On the sleeves of the B. C, CA engines
the o ring to seal the bottom of the sleeves
cost about 3.90 at the allis dealer.
If you use a SERV-A-LITE o ring number
OR236 they are about .98 cents each.
I could not find a difference between the serv-a-lite and the oem.

Jon, just make sure that the durometer on both O-rings is the same. It's hard to tell just by looking at them, but there is a difference. If the factory ring is say a 90 durometer and the SERV-A-LITE one is say a 70 durometer, then it isn't gonna handle the pressures and temps involved as well and this will cause a premature failure in the seal. Also make sure the composition of them are the same, one may be for instance nitrile, and the other may be something entirely differen. Again visually you probably won't be able to tell the difference, but it'll be there. If you want to take the time, I'd suggest taking one of the old rings to a hydraulic shop and letting them look at it and tell them the applicaton, and they can probably come up with a match. In the end though is it worth the $20 or so difference in price to go through all that trouble and to take a chance or better to just use OEM stuff and know it's right.......Just my opinion....