If you willing to get an 8-1/4 rear I’d suggest 3.21’s for a driver, 3.55’s for a hotter driver. A nice and mello cam would be 218@050 intake with approximately high .400’s in lift and 6-8 degrees more exhaust duration for the stock heads that should be milled down about .050.
This is about 300+ hp capable of moving the car into the low 14’s high 13’s (weight & gear ratio dependent) and no converter change out.
An excellent driver with reasonable mileage.