Not sure about the L-88 but I believe the rest of the Holley carbs on Corvettes were vacuum secondaries.

 

Thisis just something I read a couple of years ago.
They say the response is faster with double pumpers.
I think I read it on Holley's website.

 

I suspect that would be true with mechanical secondaries since you would have a bigger hole to cover when the throttles are slammed open.

 

Absolutely Clayton!! It isn't just the CFM that counts, it is the jets, the guts, strength of the springs, etc.. I'd rather run with a smaller CFM carb with great internals (high end Demon or 4150 or better Holley) than a bigger and "more capable" carb with cheezy internals. If your carb is mixing right and holds up to vibration and heavy use... you will be happy with the results.

I've got a polished and coated Holley street avenger on mine (with mild cam). Overkill on CFM, but responsive and no drama or maintenance.

bill.

 

All right.I put the Holley 750 dp square bore on tonight. The car already idles better. I have the feeling the carb I have been running was just plain worn out. I crackedthe throttleafter it warmed up and it had that snap I'm looking for. It sounds really good.I think that I could have rebuilt the old carb, put a looser vac spring in it, rejetted it, put a new accelerator pump on it etc and it would have run well. I got a jet kit so I can get it just right but it seems to run great out of the box. I'll check the plugs tomorrow. I tried to set the idle mixture screws but found they were exactly where they needed to be. The box says each carb is completely wet flow tested so maybe these guys set these up right the first time. We'll see. So far I'm happy. What more can I ask for?

 

More power Scotty.

 

Took the car out for a shakedown and found the throttle response about 100% better. I checked the plugs and they look a little rich. I am going to leave it alone though. The drivability of the car is wonderful. No more hesitation or bucking. A real pleasure to have something you try work.I think the carb I had on there to begin with was just junk. More power Mr. Scott!

 

While running rich will give snappy acceleration, a minor pitfall is the extra gas tends to "wash down" the cylinder walls. At least that's what I've read and heard. Might want to lean the primaries a tad. Just a thought.

 

Good point. I forgot about that. It could be leaner anyway so I'll do it just in case.

 

That's the good news and bad news about Holleys. There a lot of things you can tweek. Unless you have a dyno, sometimes you just say uncle, that's good enuf.