When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I keep reading about how the 600 - 650 CFM spread bore carb is the ticket for these engines. Is there one made to bolt to a square bore manifold, or is everyone using adapters along with the carb?
I am running the Holley 750 right now, and the only time it shows that its oversized is under 1200 RPM, after that, you can feel the secondaries open up, the whole exhaust note changes, and you fly past that Honda that thinks its quick. A quick Honda is an oxymoron, they should be referred to as "peppy" as my friend put it.
I've tried running a Quadrajet on mine and it choked it to death. I'm sure you could make it work but it might need some expert modifications. I also found that a 750 square bore worked better for me that a 650, The smaller carb had to be opened up to idle past the transfer slots to provide enough air.
I have a 750 quadrajet on my 400. It is on an edelbrock performer manifold with an adapter. If you can tune it, go for it. Throttle response is awesome, it idles nice and low, and I pull about 13 mpg before I correct for the tire size. And that is when I am stomping the go pedal.
>I am running the Holley 750 right now, and the only time it
>shows that its oversized is under 1200 RPM, after that, you
>can feel the secondaries open up, the whole exhaust note
>changes, and you fly past that Honda that thinks its quick.
>A quick Honda is an oxymoron, they should be referred to as
>"peppy" as my friend put it.
My personal opinion is that these engines love the bigger (750 cfm) carbs. To get better responce, and fuel milage, install Holley's "dog leg" venturi boosters in place of the standard straight style. The desgin of these booster increase the vacuum signal below 1500 rpms, allowing the eninge to get a better flow of fuel.
q-jet... well i would be afraid to make that statement. i like the holley square bore 4160's i'm not saying that they are the best only saying that i like them the best. if your engine is stock with the single exhaust kinda a thing. go small with the carb choice regardless of manufacturer. i like the holley for the ease of tuning and the vacuum secondaries are really easy to taylor to your needs.