Amen, Brother. The engine in my car is a fresh 350/350HP. I putabrand new 650 Holley Street Avenger on the car and could not get the mixture or response right. I changed the vacuum secondary spring several times, changed jets several times, adjusted the accelerator pump several times and nothing seemed to work. The car had a good idle and a good off idle. Now under acceleration and at highway speeds it was a different story. It would almost lay down under hard pedal and at highway speed it would surge every two seconds. I threw the Holley in the corner and put a 625 Demon on it. I put the carb on, adjusted the four corner idle, set the idle at 750 rpm and drove it. The only problem Ifound was that the vacuum secondary spring was too weak and the secondaries were opening a little too soon. I put in a stiffer spring and it fixed that. After only 300 miles of driving with the Demon, the plugs were burning clean instead of black and my mileage went from 14 to19 mpg. I have always run Holleys on all of myCamaros and never had a problem. I have heard from other people that the quality of theStreet Avenger Series is nowhere near thequality that they used to be. I have a 750 on the wifes69Camaro that I put on right out of the box in2000 and it still runs perfect. The reports that I have received indicate that there is some internal leakage in the newer Street Avenger Series which will definately effect tuning and performance. Enough ranting. Have a great day everyone!!!

We can be seen on the Hot Rod Power Tour this weekend!!!!!

 

I wasn't going to reply to this as it's pretty straight foreward...with the exception of the newer "Demon" carbs which are supposed to be superior in every way as far as performance goes, forever (my foreverbeing a 35 plus year period) any small block, from 327 to 400 c.i., (and even a worked 283) with alittle guys to it, runs the best w/ a 750 cfm carb, performance-wise. That's been the concensus forever.


1969 L46: Interesting and good info stated. Sounds like you're up on things...

 

The info put out in the string was superb and theonly reason that I responded to it at all was so that the readers had the piece of info concerning the Street Avenger series.

I have been working on cars since I was 12 and I am 53 now so, 41 years later and I am still not through learning nor will I ever be. In our car club we all pitch in and help others with their projects.

The OutlawCar Club is an eclectic group. We have mostly Corvettes (59, 65, 69, 72and a 78 Pace Car)andCamaros (68,three 69's, and two 70's)but we also have a70 Hemi Cuda, a 71Challenger R/T, a68 Javelin, a70 Monte Carlo,a 67 Nova, a 70 Malibu Wagon, two71 Chargers,abone stock 65 Mustang, a bone stock 66 Shelby GT 350H,a 23 T-Bucket, a 32 Ford Coupe, a 35 Ford Sedan Rat Rod, a 57 Ford Pickup, a 58 Chevy Pickup, and achopped big block powered 39 Chevy Sedan. I may have missed a few but you get the picture.

Although I am a Chevy man at heart I have a broad range of experience with other name plates and love to pitch inand share with others. I love to see the younger people that are interested incars and I support their interest even if they burn rice.

 

Well, I've put some miles on the new setup and the drivability is excellent. Just what i was looking for. The car is not really faster but it gets up NOWwhen you hit it. The Holley 750 dp square bore has been the carb I have used the most in my Hot Rodding life. Starting at 13 and now 46. It is a combo that is hard to beat.I still don't know why someone would put a vac secondary on a 4 speed with steep gears. It just doesn't make sense.

 

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