68 383 with 750 carb. Runs rich

Set your idle mixture with it in drive or reverse, have a friend sit in the car with their foot on the brake.

Buy the meter block it loco recommended for easy jet changes. You want a power valve rated 2" below the vac reading you get in gear @idle .

Rule of thumb for me, never use a vac sec carb with 3000+ stall converters, get a dbl pump with a 4 corner idle.