66-3X2 442

Not Joe but my 66 442 3x2 400 with 9.5 CR and a decent flat tappet hyraulic cam made 411 HP on pump gas on the pump. So I would guess 440 isn't out of the question

Cosmic Charlie

FWIW +-


Roger Huntington wrote an article about what these engines actually put out; here is the list: (All are gross hp & torque figures.)
Engine----------Advertised--Rated HP & Torque---------True HP (?)

Buick 455 Stage 1-------360@5000----510@2800------420@5400
Camaro Z/28 302--------290@5800----290@4200------310@6200
Chevelle 396 L-78-------375@5600----415@3600------400@5600
Corvette 427 L-88-------430@5200----450@4400------480@6400
Mopar 340-4 bbl---------275@5000----340@3200------320@5600
Mopar 440-Magnum------375@4600----480@3200------410@5400
Mopar 440 Six-Pack------390@4700----490@3200------430@5600
Mopar 426 Street Hemi---425@5000----490@4000------470@6000
Mustang Boss 302--------290@5800----290@4300------310@6200
Ford 351-4 bbl Cleveland--300@5400----380@3400------340@5600
Mustang Boss 351--------330@5400----370@4000------360@6000
Mustang 428 Cobra-Jet---335@5200----440@3400------410@5600
Mustang Boss 429--------375@5200----450@3400------420@5600
Oldsmobile 455 W-30-----370@5300----500@3600------440@5600
Oldsmobile 350 W-31-----325@5400----360@3600------350@5800
Pontiac Ram Air 400------366@5100----445@3600------410@560

Horsepower Hijinks: The Story Behind Factory Underrating of Muscle Car Power in the 1960s and 1970s

https://www.motortrend.com/features/horsepower-hijinks-story-behind-factory-underrating-muscle-car-power-1960s-1970s/