You live just up the road from me, too. Have you ever seen this Mustang?
That would be me.
The first thing you should do is give it a complete tune-up. I'd stay away from gears if it's your winter driver. In fact, I'd recommend you invest in some Blizzak snow tires. Mustangs are not known for winter traction, but it can be done. I did it for several years.
We do need to know what year your car is to give you better advice.
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351W 89 Mustang GT Convertible