Engine stumbles on starts and restarts.

I thought of a dozen or more issues that any one could cause this! I lost the pages in trying to post them! Twice! ---- It boils down to low vacuum by timing or valves or ign. breaking down under load! Don't ask me how it knows it is being loaded but it does! Bump up the timing and road test! Locking the weights makes for too low of setting on a 350 engine at 38 max! A 10 vacuum advance and 10 with the weights will let it crank and run on top end! A bad power valve can be the culprit! I don't run one and just jet it up 5 more sizes! Trash or float levels! Reading the plugs should give some tips! Hope it is a fuel easy fix and hoping this tiny bit gets to post!!!

If you try it after cleaning it out a few laps ,does it still stumble? If plugs are loading up you may have too much at once! How does it do siting still? Is it crisp every time or loads up after gas-ing it a few times? I have seen too much K&N oil on a filter cause this or even make the headers glow! Check your vacuum! If lower than ten you may need more timing! I run near 60 and burn all the fuel I can get down it's throat! Upping the timing with too much fuel will help vaporize it if too much, as a test if it responds better! Try lowering the float levels, you can get slosh on starts if getting too much! I lost all the carb input in my other post! I build tons of carbs of any kind and take too much for granted as just a look will tell you if its pumping enough or just look at the plugs as getting too much! All the threads will be wet! Even now! Hot, cold or next weak for that matter! Three threads of oil residue on number three should be correct! Any more and it is fat like me! Make sure your Idle screws and vents are correct! If screwed in all the way it should die, if not it is getting fuel form some where it shouldn't! Make sure it does not dribble or draw from the flow bars at idle! This will load it up fast! Was this engine always this way or did this start after a fuel pump change or valve adjustment or something that may have triggered it? It is all about testing and clues sometimes! Some changes should give enough data to decide which way to go! Hope more is a fix!

Advanced control is the way to go!!! If locked, cranking at too high of a setting limits your total advance! Check out my HEI post or other post as to getting more fire power to make more horses! A block of 6-10 with weights by making a limiting screw will let you get 38 running and still crank! No engine should have to suffer from being locked at one timing EVER!!! Valves should have a bit more lash plus .002 more for heat expansion lengthening the stem! Coming off or setting differently can change any cam profile for a better tune! I tune per cylinder by several ways to balance and boost their power! No bolt on and go racing for me! A extra fifty horses to my tuning and no dy-no needed! Just a heavy foot and a trophy! A faulty pick-up coil will lower the timing when heated! One guy had three dist. and had ruled dist. out also until my trusty meter checked them out! A Delco is high dollar but a factory stock tested used one works great! How far and what color is your spark? Check it out and throw a blue bolt 1.6 inches with-out a ground to jump to!

Yea! Now draw a pole start! Did you block it at ten degrees as to not fall so low or change so much? It will help bottom end tremendously and improve vacuum at idle to keep it clean while low enough to crank well! With weaker springs to advance quicker! Crank at 28, idle at 32 and run at 38 max! You will see the difference from locked or changing 20 degrees! A small screw with the head ground even to the shank is what I do! A machine screw with star washer or thin locking nut with a short screw as to clear plenty! Grinding the other side to clear rotor or grind out the rotor to fit! Advance to line it up and leave the slot for the screwdriver to hold while tightening the nut! A hardened tall headed screw with fine threads as to fit and wear less! 5/32 I think is the hole size! It wakes one up a bit!!!

Change the pickup in the dist..chased the same thing for a long time changed the pickup and it was gone .but I now have a great holley tuning kit lots of parts I tried  thinking it was the carb.

We have had lots of banana related things from bad switches and tachs to loose wires shorting or just a run of bad plugs or contaminated fuel! Low timing, too small of a hot wire, bad new parts or ungrounded coils! Even worn out valve guides under load! Its a big world we race in just to get to the front by finishing! Make sure of your valve springs and settings of the clearances! Have you switched intakes or checked for low vacuum or just bumped the timing up by hand! Will it load up if throttled quickly 3-4 times in a row? Does it cough or miss or just hesitate before correcting itself???