Anybody Actually Goin' Fast With a Holley 3 BBL?

[Salvatore]

In my days I was always told that a smaller carb that runs 85-90% efficient is better than a bigger carb that runs 60% efficient. I always had good luck with the 750 double pumper in the 70's on my LT-1 nova. That carb seemed to run better out of the box than the 780 I started with that had small modifications. I also was under the impression (from the guys who ran it) that the 3 barrel Holley was a bust. At least in the early days it was. Racers would put it on their LS 6 chevelles and slow it up in both et and mph. But like I said this was the 70's.

[Kim_Howie]

Talk about going to get toasted. I love my Carter carbs. They don't leak, there very responsive and idle better than any Holley I have owned.

[StealthBird]

The Motion gear drive kit was developed because back then, there was a definite attitude in enthusiast magazines that vacuum secondaries were for station wagons, not for performance. We know more nowadays of course. Vacuum secondary carbs produce just as much power as a mechanical secondary carb, they're just harder to dial in because they don't have a secondary metering block, just the plate. Drilling holes was time consuming, and swapping in a metering block was easy. Besides, you drill some holes in that vac secondary plate too large, you're sort of screwed. That's why most shops opted to replace the plate with a block, and then go to the gear drive. More of a shot off the line, in race trim, with slicks, but there's a lot to be said for vac secondaries on a street car. Once the butterflies are opened up, there should be no difference. The problem is tuning that secondary....

Just for the record, the larger Holley 3-barrel is a 1030 cfm unit, not a 1050. The only difference between the Holley 950 3-barrel (3916) and the 1030 cfm (4604) is that the 1030 uses dump tubes for the secondaries, no boosters, similar to the way the Q-jet works. The primary circuits are exactly the same as an 850.

I've been using a 1030 on the street for several years now, and have swapped back and forth with a 950HP. The 950HP is more responsive, understandable as it has smaller venturi. Wide open throttle, seat of the pants, can't tell a difference.

I know that's not scientific, just wanted to throw away a couple pennies today, so that was my .02 cents.

[Plowman]

On the 1968 Dana of Brian H,has a Holley 3bbl,he is doing!

[PxTx]

I saw that, looked like they had the Eelco secondary squirter kit but with the vacuum secondaries left in place. Probably the best setup going!