FAST racing improves the cars, and it's proved by the quarter miles timeslips. This 383 Road Runner was worked on in all the right racing ways, and though appearing to be a restoration, it's now doing the 1/4 in 11.5 sec while still using factory exhaust manifolds and 6 inch stock tires

read about it at https://www.hotrod.com/articles/1969-plymouth-road-runner-consistently-runs-high-11s-makes-505-hp-stock-v-8/