Michael,
I think Bill Martin is on the right track to solve your problem, but the
puzzler is that 3 carbs all performed the same way???
What is the vacuum at idle? Is the power valve OK? With a stick car it is
not usually a problem with low RPM as the car is not idling in gear under
load loading up the cylinders with fuel but if you hold it for a few seconds
it would clean out if the power valve is not working as it only applies to
the idle circuit. If the surge is there always between 2000-3000 it sounds
like an overrich condition and you should work to get more air in the lower
throttle positions.If you have a rich condition at low RPM Bill pointed to
the secondary butterflies and you can drill a small hole to allow more air
in. I did need to do this once in the past but if you just need a little
more air rather than drilling first I woul try to open the secondary
butterflies with the stop screw from under the baseplate. Normally it is a
small fat set screw. If it is running rich and the Idle tranfer slot is not
permitting enough air for idle you may need to work with the idle air bleed
screws but I have only done this on our BLP carb and it has replaceable
bleeds making it easy to adjust. The holley is drilled and may need to be
opened up to allow a little more air (I think???). The surge does sound like
a Carb issue and the fact that 3 carbs acted the same makes me wonder?
Hope it helps,
Tim Ronak
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