Thanks, K. I have a YZ400 piston kit-and is actually just a bit over the next 390 oversize. Have a National in October and with back to school expesnses etc, it will all help get me going.
BTW Wiseco claims to have 390 pistons, but the better Wossners seem hit and miss to find in stock, while I am sure there are Mahles out there they are surely high $.