'1967 Holiday Race' ~ Plymouth GTX 440 vs. Pontiac GTO 400 'Ram Air'

The 670 head Ram Air 400's flew with proper gearing. It's always important to reference which "Ram Air" and year. That year with the 4.33 was a potent combination. Much quicker than the later Ram Air III. Probably similar performance to the later and more powerful Ram Air II and IV, which were in later/heavier cars.

The Ram Air IV never came in a car.

EDIT. Sorry, I was thinkin of the Ram Air V.