Jetting my carb??

I am running same dr. gas, 3" all the way, 347, victor jr. with victor jr. heads and a 4150 815 CFM carb at 3000 elevation and get best dyno power with 88 rear jets and 80 fronts. If i were to guess I would try mid 70s jets to start with your set up.

First off, jetting does NOT increase airflow. Also, the higher the elevation, the smaller jet you need. Since the air is less dense with oxygen at elevation, less fuel is needed. Until you get your AFRs on there, I think mid-70s jets will be way too rich. Most Holleys in the 600cfm range usually have 66-68 jets from the factory, which is often a little rich for a stock motor.

Since you are not changing heads yet, I would guess that your stock jets may be just fine. You could always call the Holley tech line for advice.

Once you change heads and cam, you will be changing jets again anyway.

You may want to consider a 750 once your motor is done.

Leave the jetting where it is and drive the car. A header change should not affect jetting. Increased airlow into the motor will. As an example I recently installed an carb tray to increase flow into my set up. The AFR changed from 12.8/13.0 to 13.7/13.9 to 1. That required an increase in jet size. The headers will NOT get rid of the "bog" when you go WOT. That is most likely caused by a lack of fuel. It could be caused by a number of things.
Ron

Your bog is probably an accelerator pump problem, but could be many things. Throw a kit in your carb, and check the jet size when you are in there. Then run it for a while and read the plugs.

I would first look at the pump operating lever clearance. There should be "zero" clearance between it and the over ride spring.

Ron

I would take a vacuum reading as the next step, and make sure that you have the right power valve, based on the vacuum. There may be a delay in opening the valve causing a "bog", or it could be dumping too much fuel.
I looked at what BG ships their 650 CFM with as far as jetting, and they suggest 71 & 79. So I might start with a 68 & 74. Always try to keep a six size spread between the P and S. Run the car and read a couple of plugs.

Ron

I just started having major problems with my 650V Speed Demon tonight, I was barely able to get the car home. About 4 miles from my house, I had to stop for a light to turn left, well the car started running really rough and almost stalled. I quickly put it in neutral and put my foot on the gas and I was able to keep it running.

At part throttle (or idle) it was running REALLY rough, like it was missing a cylinder or something so I thought to myself "Oh great, I have an ignition problem". At every stop light I had to either put it in neutral and stand on the gas, or two foot it to keep it running. A block away from my house it finally died, and would not start again so I pushed it home.

When I got home I checked the ignition, and it was getting spark. When I tried to start the motor again, I would get nothing unless I gave it full throttle, after which it would pop a couple of times and then die. I looked at the carb and noticed fuel dripping out near the throttle shaft. This would lead me to believe the floats somehow are too high, but I have my float levels set perfectly so I don't know what's going on

I'm gonna let it sit overnight, and let any pooled gas in the motor evaporate and try tomorrow.

""Dang I don't have the tools to do the vacuum readings and I don't have any extra jets. I am gonna screw this up. Any other suggestions.""

Yes, buy the tools or bring it to someone who has them.

Make the investment. Not very expensive. www.summitracing.com has the jet packs for $39.95. I checked ebay and found one that has a bid of $9.99. Here is link: http://cgi.ebay.com/ebaymotors/ws/e...tem=7910380702&category=33551&sspagename=WDVW

Ron