My car's specs are in my sig. When I really step on it, initial take off is good, but as I stay on the gas hoping to really haul ***, it just seems to drag. A very little bit of smoke exits the tailpipes - almost not enough to see. Burns no oil.

The A/F screws are out 2 1/4 turns.
I am using ported vacuum advance.
Initial timing is 10* BTDC.
Plug gap is .045.

Does anyone have suggestions on what I might be able to try in carb tuning, vacuum advance or timing to get the lead out? I know my 2.73 rear is a major downfall. I still think I should be able to accelerate faster and more consistently.

Any ideas are appreciated.

 

A few things to look at:

• carb jetting (calibration)
• clearance between carb air horn and breather lid
• fuel delivery

Idle mixture screws are a non-issue at WOT. Edelbrock sells a jet lit for that Carter carb, you should get one and see if you can get the carb to match your engine & car better.

#2 is a real problem that alot of people seem to be in denial about. Consider your hood clearance to the air cleaner; with the stock air cleaner and relatively low-rise intake, the air cleaner almost touches the hood, and there's about 2" of space between the top of the carb and the bottom of the air cleaner lid. Now imagine that you add a taller intake (moves the carb up insiode the air cleaner) and "drop" the base of the air cleaaner. What you have just done is narrow the "slit" around the top of the carb, replacing a restrictive intake mainfild with a restrictive air cleaner. It doesn't matter how tall the piece of paper is, if the air has to all squeeze through a 1" tall slot around the top of the air horn, you're not only going to have a restrction in the usual sense, but also the air has to make a sudden 90° as it enters the air horn; it will be turbulent and full of eddies; there's no way the carb will meter fuel correctly or consistently. You can check for this by simply removing the hood and the air cleaner and seeing if the car runs right.

#3 is also very common. You can easily check for this by running the car hard until it starts to screw up; then while it's doing the bad thing, instantly cut the key off, take your foot off the gas, and take the car out of gear at the same time. Do all 3 things at the same time, and coast over to the side of the road, and take the air horn off the carb so you can look in the fuel bowls. Make sure you turn the key to "Off" and not to "Lock" when you do this!!! Also remember that you will lose power steering and brakes. If you have a fuel delivery issue, your fuel bowls will be low, or even almost empty.

 

Those carbs are generally rich on most applications, that might be the problem on yours. Maybe its lean although I doubt it from what I have seen. I havent messed with a carbed 383 before, but maybe if you tell me what size jets and rods is in there now I can give you some direction. The numbers are stamped on the parts.

 

The jet and rod sizes perspectively are .113 and 1453(071x047).

My intake is higher than stock but i have a flat base air cleaner and a cowl hood scoop. So air should be ok coming in.

I have 1 5/8" headers with dual exhaust, so there should be enuff room for exhaust.

This is my first carbed car so I am leary of changing jets, but I know I can do it if that is what needs to be done. Maybe the step up springs need to be changed.

Thanks for the help!