Carb Suggestions

[ctreser]

I've got a 440 in a 66 coronet that currently has a old 750 VS Holley. Was wondering if it could handle something a little bigger or mechanical secondaries.
Suggestions on replacing my old carburetor would be appreciated.
Will see mainly heavy street use with little track time.


Weight 3800 lbs
.030 over
67 915 heads. No info on work done.
Weiand Dual Plane
.501 cam
727 2800 stall converter
Doug's 2" headers
3.91 with Eaton Tru Trac
Forged pistons. No info on what type.

 

[snakeoil24]

It will work better with Vacuum Secondaries and I larger carb will do nothing.

 

[Dennis H]

850 Demon works good on mine.

 

[mopar 3 B]

Even tho many here will not agree our local racer and 440 engine builder of many years would tell you unless properly tuned your 750 is all ready to large.

 

[Cranky]

Then I'm guilty of running too much carb even on my street cars. I've always leaned towards drag racing them and many of my cars went faster with a larger carb however, some didn't like it and some did. How bout a 600 Holley DP on a 289 Mustang with a 4 speed and 2.80 gears for one example? Got 21 on the highway but only 12 in town. That's one of the problems with mechanical secondary carbs. Your regular in town driving will suffer and most likely foul plugs too but there's only one way to find out what 'your' engine will like and that is to try it. It helps if you have someone that can lend you a carb and doesn't mind you tuning it to suit your car. Btw, That old 66 Mustang Fastback ran a 15 flat crossing the line in top of 3rd but man, it had a pretty good top end with those 2.80 gears lol.

 

[lewtot184]

will too many carbs make your butt big?

 

[ctreser]

Thanks guy's. That's a lot of variables there. I think I'm leaning toward the AED 750 HPHO mechanical secondaries. The 850 vacuum secondaries sounds interesting also. How many others are running mechanical secondaries with automatics.

 

[mopar 3 B]

Mechanical but not a Holly

 

[lewtot184]

truth is that you may gain more from an intake change than a carb change.

 

[ctreser]

truth is that you may gain more from an intake change than a carb change.

Your probably right. checked the model and it's a older 7500. Would a Performer RPM be a decent choice and would it fit under my hood.

 

[Garys1969RR]

I am running a 451 with the 509 cam, headers and ported 915 heads with larger valves. Holley street Dominator. Automatic. Had an old 3310 780 vac sec on it for awhile. Ran 12.54 @ 109 with that carb. I put on an 850 dbl pumper, now it has ran a best of 12.33 at 110. So in my case, bigger is better. Runs real consistent 12.40 /110 MPH

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I am at 5400 feet where the air is thinner, so I suppose bigger works better at this altitude where there is less air pressure.

 

[lewtot184]

Your probably right. checked the model and it's a older 7500. Would a Performer RPM be a decent choice and would it fit under my hood.

the edelbrock is taller but a dropped base air cleaner will probably let everything clear. the rpm intake may be worth 20hp or what you have.