318 Poly Flow Test

Not really an A-Body thing, but a cool engine none the less. My first car was a 1966 Coronet 440 with a 318 poly. My father bought it new. I've had the heads in the shop for quite some time, and I finally took the time to rig up the valve opener and flow test the intake. Small ports and not much flow, but these are cool heads. Nice, centered, unobstructed intake port. Combustion chamber with canted intake valves and quench area on both sides. Short, direct exhaust port. Nice design for the 1950s.

Flow numbers are attached. Flow numbers from an iron 360 head with 1.88 valves are included for comparison. Poly has 1.84 intake valve.

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What is the springs installed height. The 1.88" Magnum valves could probably be installed easy enough. For low cost the LS 1.9" intake could also be employed. Get the GM powdered metal guides or bronze. If the installed height is about 1.8" the LS beehive springs, retainers and keepers can be used.