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Old 01-11-2026, 07:50 PM
ericwoo ericwoo is offline
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Join Date: May 2025
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I apologize for extending this thread to the point of being annoying, but just wanted to state what I found out about my carburetors.

After watching a youtube video, it turns out my original Holley 600 cfm carb from the factory didn't drill out the hole from the primary venturi to the vac secondary! So I have been running only on 2 barrels the whole time. But it still ran mid 14 seconds off 300 cfm which is pretty good imo.

I contacted Holley to ask what size hole it needs to be and drilled it out myself. I just tested my Holley 600 today and this 350 is running mean with that carb. It may even be running better than my Holley 670 street avenger but I think that is because the 600 has a lighter secondary spring in. I'll look into tuning them before the track in the spring to test both.

Seems I have had 0% luck in every aftermarket part in being manufactured correctly. IDK what is up with that but quality control must've been non-existent in the early 2000s when everything was ordered.

I was also curious about the quardrajet. I rebuilt one with the high performance parts with the recommendations for my engine, read through the book with a lot of time put into it. It is possible I did something wrong but my engine did not like it at all. It runs fine as a daily driver but the holley's performance is quite explosive in comparison. Quadrajet seemed to just tame my engine considerably and was a big disappointment. Night and day difference in performance.

Quote:
Originally Posted by steve25 View Post
How is your car sitting, is the ass end higher then the front and if so by how much?
Forgot to reply here. The front was lowered before taking it to the track and the rear is the original height. This may not be the best picture. I recently installed a front spoiler.





I'd bet I can get this 350 to do mid 12 seconds. It is running wild now with these holleys and I havent even got into tuning them to perfection yet.

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