Ordered a +2 rear (47T) sprocket and new chain.
Will be replacing my rear sprocket with a 47T, up +2 from the stock 45T as this will give me more torque and more pulling power in 6th gear.
Noticed that 6th gear is geared too tall more like an overdrive gear. Going 2 up in the rear will give my 6th a bit more pulling power....
Didn't want to go -1 on the front sprocket, as that will be equivalent to a +3 at the rear, which may be too much for a 390 single...though more expensive than just replacing the front sprocket, by doing this mod....replacing the rear to a nice looking aluminum sprocket and a gold chain will give my 390 more performance with "bling" factor.
Keep you guys posted when its done.