Holley 670 Street Avenger

I have a 670 avenger on my car.
After several carbs I like this one the most.
BUT it depends on what you want from the car.

I am not trying to get every last HP out of my engine.

I lost high rpm response for sure.
Mid range power band is very good.
It is very well behaved in slow, stop and go traffic.

I set it up for my application and have not touched it since. If you are looking for a hassle free street carb, I would recommend it.

Doug M

I have one as well. Put it on my stock late 72 351C (Performer intake, Mallory Unilite electronic ignition, and headers) and had it dyno tuned on a chassis dyno. 249 hp at the rear wheels. Very driveable on the street. I've been told the Cleveland responds well to a larger carb, but this is what I have now and I've been pleased.

Thanks guys for the info. I had a 650DP on my car for years. It was tuned a few times and was very responsive but I could not get rid of unburnt fuel smell. Then I tried Edelbrock AVS, it was very well behaved at slow speeds and in stop and go traffic but was not very responsive at high RPMs. Next came the Quick Fuel 650 DP. The secondary actuation was hard to adjust and it also changed the deep sound of Mindtrain exhaust system which was unacceptable to me. (I've had people follow me just to hear the exhaust). I've heard good things about 670 Avenger. I want a decent carb for street with good mid range throttle response and is easy to tune. Any advice is highly appreciated.
Thanks
Shah

I agree with the other posts. I have a 770 street avenger on my fairly aggressive 427 (294/300 duration roller). It's the only carburator I've used on this motor so I can't compare to other carbutators, however, it's very streetable - smooth and responsive and the electric choke works real well. I set the floats and mixture once and haven't worked on it since.

In normal speed it's superb. But in high speed it starts to vibrate...

quote:

I want a decent carb for street with good mid range throttle response and is easy to tune. Any advice is highly appreciated.
Thanks
Shah

Us guys here in NH are running the Demon 650 with vacuum secondaries. This seems to be an excellent carb. I just dyno tuned mine and was able to run 13.5 air/fuel mixture for the entire pull. I'll try to upload the dyno graph. I was like you and only wanted a steady performer, not squeeze every last HP out of it. Through stock Ansa's it did 268 HP and 332 TQ. not too bad and its really smooth curves. My tuner thought we might go larger on the secondary jets but I'm really happy.

Highly recommended carb. Demon 650