273 commando Build

Plymouth 65 said
Didn't know the 920's had the same combustion chamber volume and flowed better. The early 273 does have a different bolt angle. 65'

Small Block Cylinder Heads

CC's / Port Volume / Size / Flow

1966 - 1967 {273} Casting #2658920

Heart-Shaped Combustion Chamber

Factory CC Level..........................62.0 to 65.5 CC's
Recommended Minimum CC's......57.3 CC's

Intake Port Gasket Size...............1.05" x 2.07"
Exhaust Port Gasket Size.............1.14" x 1.59"

Intake Valve................................1.78"
Exhaust Valve..............................1.50"

Intake Bowl Size.........................1.53" {86% of Valve}

Intake Port.................................125 CC
Exhaust Port...............................61 CC

Intake Flow...............................160 CFM @ .450" Lift
Exhaust Flow.............................107 CFM @ .450" Lift

Intake-to-Exhaust Flow.............64.8%