According to Super Tuning and Modifying Holley Carburetors by
Dave Emmanuel page 23 reads "..., part number Holley 0-3310-1 has
the same venturi and throttle bore dimensions as the 0-3310-2, -3, -4, yet it
flows 780 cfm as opposed to 750cfm. The 30 cfm difference in flow
capacity is caused by a more restrictive booster, which in turn offers a
stronger signal."
Also, the 3310-1 is listed by Holley as a 4150 model and the 3310-2,
3310-3, and 3310-4 are 4160 models. The 3310-1 has metering blocks in
the primary and secondary bowls to allow jet changes on both sides; whereas
the 3310-2, -3, -4 have a metering block in the primary fuel and a
metering plate in the secondary- which does not allow jet changes.
My two cents on which carb to use is the 3310. I personally own a
73 Chevy C-10 with factory 454, th400 combo. It is stock except that I
have changed over to HEI, added an Edelbrock Performer (oval port) and run a
Holley 3310-1. I have great throttle response and get "decent" mileage;
with 3.08 gear in town I get 10-12 mpg and 15+ highway. Once I have
enough Benjamins I'll be looking for a 70 Chevelle to transplant the motor and
trans into.
