I need opinions on this 318 build

Let me start over a bit , the car is an unfinished project that i recently purchased . The PO rebuilt the motor and had a 727 transmission built and then installed everything . I only have basic info on the motor build . Nothing was plumbed so I got everything done so I could break in the cam and just check the general health of the motor . As far as gears the car has a bone stock 8 1/4 . What I see in the future is no more than 3:91 gears and really leaning towards 3:55 if I can make them work and 15" wheels . Primary use will be street /cruise with occasional track time .