going to cost way more time and money than you will be willing to expend to do this. upgrade to a truck with a 10 speed or live with your set up.

but anything is possible with enough time, money and know how…

ford battery, oem too and original to your car. dont play around with it, just replace it. try and find a deka or eastern penn brand battery, they have no vent caps like the ford battery does but instead little vent ports on the side. they will not leak like this one does.