Racing Fuel Systems

Which carbs would work best? 500, 650. I don't see any 650 listed T ram calibration. Mopar 446, 271 @50 590 cam, 5200 convertor. Suggestions?

I don't see any horsepower numbers in your post. Street or strip ?

A pair of performance 650s is good for engines capable of of up to 800 to 850 hp on a tunnel ram. 750s are suitable for 850 to 950 hp.
So unless your in that hp range smaller than 650 will work better.

650s. Small primaries for improved throttle response, bigger secondaries for flow.

It might be good to know that a tunnel ram is not as cfm dependant as a dual quad intake manifold or dual plane intake.

David Vizard
"First, the port runners are a straight shot to the cylinder head ports, so the manifold is more flow efficient. Second, the carb barrels are directly over the manifold’s port runners so fuel distribution problems are minimized. Third, most wet flow problems arise due to a runner’s change of direction but because a tunnel ram’s runners are almost straight it has fewer issues with wet fuel flow. Finally, the pressure-wave tuning brought about by the interaction of the plenum and the port runners is far better than with any single-carb intake. All this adds up to a better result for a given amount of carb CFM."