I've been very happy with the 370's on our Westy.  We replaced the DPO's
choice of under rated tires and found these to be a huge improvement in
crosswinds and for general driving.  Just checked the receipt from when we
bought them and went out to physically check the tires.  There is no
notation of the "B" designation (as in Y370B) anywhere.  Could this mean a
B-stock item (i.e. a blem)?  This might have something to do with your
handling problems.  At least worth a look.

    As to David Johnsons question about winter handling, I've found them to
be excellent.  I wouldn't have to have chained up at all last season but for
the cars in front of me stopping on the ice.  Plenty of traction if we kept
moving and smooth, but once we stopped...out came the chains.

Mark
82 Westy