Corrected Horsepower Factors > 340 ~ 360 ~ 383 ~ 400 ~ 426-S ~ 440

RE Quote:

1969
Plymouth 'Air Grabber' {Under Hood Fresh-Air Induction {Code N96} ........... $55.30
Dodge 'Ramcharger Hood' {Code N96} .................................................. ... $73.50

Both of these Fresh-Air Package Units did 'not' change the 'advertised' Factory Horsepower ratings.

The Consensus > Was that they were worth approximately {+7 Horsepower} at 90 MPH.

Personally, don't believe any measurable effect on horsepower with air grabber type scoop (I bracket raced a new 1971 RR 383 auto with air grabber back in the day). For 70-72 it would be easy to verify during track conditions, just close the trap door every other run and then compare all the quarter mile ET's and MPH with the other 50% made with the scoop in the open position.