I have a 68 convertible which appears to be numbers matching, it has already been repainted a different color, and the convertible top does not match original color. The carb has been replaced with an edelbrock. As well as some floor pan replacement work was done.

I am curious as to what I can upgrade without affecting the resale price of the car.

The engine and trans need to be pulled and redone as they are both leaking pretty bad. Some of the items I would like ot upgrade.

Rearend gears: As it has the 3.08 which is great on the freeway but lacking any fun light to light
Internal Engine components: To add a little power
Front Brakes: Upgrade to disc as it is 4 wheel drum still
Transmission: Prefer a manual

Any and all suggestions are welcome, if I cannot do much, then I will most likely just replace existing brakes, fix the leaks and sell it so I can get a car that I can go more towards pro touring yet keeping the classic look.