[Ant]

Originally Posted by greg schroeder

I guess there are assorted opinions. For me I sort of like the idea of best throttle response, linear throttle response, less weight, more power and getting it to stick to the street. If I did it again I'd definitely get another single Pro-Systems unit with single plane intake and Mickey Thompson ET street drag radials, 275/60 15s rear.

Pro-Systems carb without air cleaner
Pro-Systems carb with air cleaner
SAE corrected wheel power, 427W(small block), non-Superformance exhaust

Greg,

I have a Pro-systems 950 road race carb much like yours on my 373, I think its actually a 750cfm but flows more, with over 600bhp I have only dynoed the engine to date, but I think the mechanical secondaries with the fuel pump squirting would give better throttle response than a vacuum secondary carb for road racing, sort of kick in the pants coming out on a turn. The dyno guy compared the response of my engine to a fuel injected engine for nice progressive power. I dont think I will be changing to vacuum secondaries, but I have raced on them and they still work good! Selecting the right carb and calibrating to suit the engine, correct size are important, and with the Pro-systems carb it has some clever attributes over a standard Holley, I havent had a carb out of the box ever run as nice as this one! Keith Craft has done a nice job selecting the parts for this custom built road/race engine.

I have seen some real serious US$3-4000 carbs for racing with clever emulsion blocks etc that cover more track situations, but they are on high tech Transam, and probably Nascar total race engines