Holley question

[427TJ]

'55 Chevy, 327, Duntov solid cam (rumpy idle), MSD mechanical advance dist (no ignition box--has the blue box under the base), Holley Street Dominator intake, supposed to be a 10.5:1 engine, headers, turbos, 4-speed, 4:11s.

Has an ancient Holley 650 spread-bore now that needs rebuilding/replacing.

Is a 650 double pumper (new in box) too much carb?

I re-read the carb section in "How to Hotrod Small Block Chevys" and they say 650 is as big as you want to go for a street/occasional strip SBC. Book also recommends the Holley spread-bore and the vac-secondary units as good street carbs over the double-pumper. I was thinking double-pumper due to the big cam (too big, really).

Recommendations? Thanks in advance!

[Keith Tedford]

I would think that the 650 spreadbore would be next best thing to a Quadrajet. I'd rebuild it. I'm doing one for our el Camino which has a mild 350.

[VintageMusclecar]

My $.02;

If it's only going to see street driving duty, I would strongly recommend an early 3310 "EH" or a 3310-1. I've said time & time again, the early 3310 is one of the best "all-around" carbs Holley ever built.

As far as the spreadbore carbs...I have never been, nor will I ever be a big fan of them. If you want to run a spreadbore carb, run a Quadrajet.

Eric

[CamarosRus]

Bill, I would go with ERIC's advice and be done with it !!!!!

[MosportGreen66]

I would also take Eric's advice... Here is a neat write up about the 3310 in this month's Hot Rod!

[ORIGLS6]

I agree 100%, and not just because the Carb Guru says so.

Like others including Sammy (in another thread) have said, I had no good experiences with the Holley spreadbore, and I'm a HUGE fan of Holley carbs.

As far as the 3310 that Eric recommends, I ran one on a 292 CI SBC with a GM aluminum hi-rise and the old .030-.030 cam and loved the way it performed. The 3310 is an extremely versatile piece. Just jet it correctly and you'll be happy.

[427TJ]

Thanks again everybody, I have PM'd Eric for more advice.

In 1980 I had a '67 327 (built for Friday night street races) 4-speed Camaro. I bought a 780 vac-sec Holley off of a bulletin-board ad in the local speed shop for about $100. The seller was a Holley engineer (he said) and called the 780 I bought a Z/28 carb. It needed NO jetting or adjustments of any significance and it performed very well. I was sorry to have let it go when I sold the car. I remember thinking that I should buy a new Holley and put it on the car and keep that great 780. Oh well!

[Keith Tedford]

I was just going on the personal experience I had with a 650 spreadbore that I used many years ago on a 350. Must have been lucky, because it worked quite well for me. On the other hand, the experienced guys here see a lot more carbs than I ever will. I'd take their advice.