This info comes straight from someone that woods ports saw for a living and is a dealer too. What he says about the aftermarket BB372 option.
NOT ME SAYING THIS GUYS
I just installed and ported one of the new BB 372 kits from Bailey's.
These are a lot nicer then the ones that I have seen for the 046s.
It actually fit on the saw with no mods to the case.
I guess I should start off by saying there are a lot of people that are saying this is nothing more then a bored out 372 cylinder and the way the ports are laid out that it will be detuned. That's bull. These claims are made by arm chair people that have no knowledge other then what people tell them. They never had a degree wheel on them and probable don't know how to use one in the first place.
The cylinder is NOT cast the same as the stock ones are. There is a noticeable difference on the outside at the top of the transfer ports and the cooling fins in that area.
The kit that I have has excellent darn hard chrome plating. The base metal seems strong, not like some other cylinders that I have cut. There are a few casting marks here and there but they can be cleaned up very easily.
The port timing numbers on the BB 372 are 163 Exhaust, 144 Intake, 119 Transfer. The stock 372 is 161 Exhaust, 142 Intake, 114 Transfer. That's only a two degree variation on the intake and exhaust. I doubt that anyone could tell a two degree difference in engine performance.
The exhaust port on the BB is not cast as wide as the stock one. There is also less metal cast in that area but it can still be cut wide enough for the saw to perform well.
I didn't CC the combustion chambers of both cylinders but with the naked eye I could see no difference. I will check the next one I get in.
I didn't run the kit in stock form because I have no interest in stock saws but it should out cut the stock ones and have more grunt at low end.
Once ported they work real well. This one will cut right with one of my ported 2171s with the ported Husky 375 cylinder.
I think this one will be a winner. They have it prices reasonable and the quality seems excellent.
I will give Bailey's a big thumbs up for this one.
If you melt a piston on your saw you might as well just buy the BB kit from them, it doesn't cost that much more then a factory piston.
This kit will fit the 365,371,371K,375K,372 and also the Jonsered 2065,2165,2071,2171.
I don't see how you can go wrong with one of the new 372 BB kits.
I just wish that I had one of my own to play with and to run farther testing on.
So there it is, your choices are 372xpW, 375K, BB372.
Yeah I may have ran one before. 
:greenchainsaw:
