never did, but would guess from 1/4 " to 3/8" tops allowing for a some wall thickness.--as you say just for balancing at idle. The manifold shape was a slight horizontal "s" shape to match the head port size. The intake roar thru some small paper air cleaners closly imitated the exhaust pulse (probably more so than a triple setup on a log manifold- offy), they were louder than stock mufflers!
Take a brake cyclinder hone and open up the venturi and blend it down to the throttle bores and try for the late model diameter. bigger can be better!
due to cam lope, I had to safety wire air cleaners with some guitar type strings to prevent loss when engine shook them off! Just drilled a slight depression in air horn lip to allow air cleaner set screw to have a good "bite", an bolted other end of guitar wire to float bowl screw- had sort of old Airplane look to it.
These carbs will have one last accellerator pump discharge went engine is shut off, and air cleaners can receive a dose of raw gasoline if not parked level-- could be 3 Molitov coctail effect. When used on a Nash-Healey they had a metal drip tube ('bout 12 to18" long) threaded into the bottom of the carb to collect this raw gas and escort it safely down past the hot exhaust manifold. The chevy carb just had a threaded plug at this location. Intake manifold vacumm kept the accellerator pump in the lifted position until a lack of vacumm allowed it to overcome a spring sending a flush of gas, instead of hard linkage doing the job.
Last edited by preacher-no choir; 11/17/11 02:59 AM.
