1/4 mile ET guesses

Sputtering is probably valve float. Back in the day, I bought a new 70 Duster, 318, manual 3 speed, open 3.23, f70 14 tires.

Same thing, mid 15's. Installed a holley 500 sbbl. So rich, took a month of learning how to tune a holley, still too much carb for the engine, but it stopped burning my eyes.

Then old school traction bars, and played with them until both tires spun.

Then heavier valve springs, to stop the float.

Then is was a 14.95 car.