I have a 292 bored 60 over mummert intake and headers. Pertronix in dizzy. I have been running autolite 46. I believe i have around 10k miles on the motor since build about 5 years ago. I have a new avs2 500cfm carb. I have this weird hesitation that only happens in the higher rpm 2800 ish. Seems to only happen when i really get on it. if i ease up its not as apparent. This carb has capability to adjust the air flap for secondaries. Could i have it too loose? Also I have the accelerator pump arm in bottom hole for least amount of initial shot. Stumble off the line is bad in the top hole and simi in middle hole. I am not a pro at reading timing. would this be a symptom of too much timing? Also i am thinking of going to the autolite 45 to see if my engine likes them better. here are some pics of the plugs. thoughts?
 

Hesitations can be tough to diagnose.  Your plugs look good to me.  I think your problem may be in the distributor or timing.  Get a timing light that has a degree wheel dial on the back.  Mark the TDC line on your crank with some white paint and disconnect your vacuum advance. (I assume the TDC mark on your crank is right?).  Start the engine and make sure the timing mark isn't jumping around or flashing.  If it is, you have an electrical problem. (how old are your wires?  Are they shorting out somewhere?)  With your engine running, make sure the TDC line is stable and moves smoothly as you rev the engine,

If all that is good,  Set the dial on the back of the timing light to 36-38 degrees.  I run high test gas at 38 degrees.  Set your distributor timing so the TDC line is on the pointer at full advance and lock it down.  Reconnect the advance hose. My bet is somewhere along the line you will find a problem.  Most carb problems aren't the carb.

I am running a stock 1957 distributor in my motor.  I recently pulled it out and went through it because I had an inconsistent idle.  Upon disassembly, I found that I failed to connect the internal wire grounding the mounting plate to the case.  This means the ground was going through the balling bearings on the plate.  While I had it apart I lubed everything and installed a new set of Mr. Gasket advance springs.  I also found the stud that holds the vacuum advance arm was loose.  I repaired these problems and timed the engine as above.  My engine now runs better than it ever has.  Idles great, runs smooth and pulls hard.  I posted this because others may have the same issue.

Your spark plug looks good and a colder spark plug is not recommended.  Based on the color change on the electrode, the overall ignition timing also looks good but the ignition curve itself could be questionable. You don’t mention if you have the vacuum advance hooked up but if you do, then check to see where it’s hooked up to the carburetor.  If it’s hooked up to a direct vacuum source, then change it to a ported vacuum source at the carb and see if that helps.  Be sure to set your ignition timing with the vacuum advance unhooked.
 
From your description where the hesitation is not as bad when backing off from the throttle, then you may have a lean spot in the carb.  This could still be a symptom of the distributor vacuum being hooked up in the wrong spot or the timing being set with the vacuum advance being hooked up.  You might try richening up the idle mixture screws first and see if there’s any improvement.  After that, richen up the primary side the equivalent of a couple of numbers.  You’ll need to change both the jets and rods to accomplish that.  Short term you could just try using some smaller diameter rods on the existing primary side jets and while this may be ultimately on the rich side, it should give you an indication of what the carburetor is wanting.

Lorena, Texas (South of Waco)

Upon disassembly, I found that I failed to connect the internal wire grounding the mounting plate to the case. This means the ground was going through the balling bearings on the plate.

This is the main cause of the balls on this type of breaker plate going out of round, a bad GRD and the balls becoming the GRD. They are also becoming hard to find.

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This carb has capability to adjust the air flap for secondaries. Could i have it too loose?

Fine tuning is included in the EDEL INSTR SHEET.

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Thanks guys I will try a few things. I dont have a dial back light but I see that I can try to get timing good with a vacuum gauge. Any pointers on that process? I assume i should plug all vacuum line to carb first and set it to highest vacuum reading then back off just a tad. This is dont by the manifold vacuum port on the card correct? This would be the largest port on from of the edelbrock that is used for PCV? 

Get a timing light and do it right.

The manifold vacuum port is one of the smaller 3/16" ports.  Refer to the carburetor's manual.  You can also tell by checking for vacuum at that port with the throttle closed and engine idling.  One should have vacuum and the other should not.  The 3/8 port should work as well but you then need an adapter.


Lawrenceville, GA

Don't really need a dialback timing light, they are nice to have, but all you really need is a standard timing light and the balancer marked out to 50°, can easily make your own timing tape with a little math. Disconnect and plug the vacuum advance and see that the centrifugal advance moves smoothly to say 34° to 36° as you rev it up. Re-connect the vacuum advance, the timing should be close to 50° when revved up.

I just had this problem. Does your carb have a slight glass on the fuel bowls? Where is the fuel level at? The cause for mine was low fuel level. I recently swapped out fuel pumps and didnt check the level afterward.


Durham Missouri

Thanks guys. I put my standard timing light on and I dont have timing tape on the balancer. I did read that if you had to do it by ear you can advance the timing at distributor until the rpms stop climbing and then back it off a bit. I did this and my truck is running much better. I dont think i hear any pinging.