flooding out or something else

i think i've got carb issues. but as i'm getting deeper ad deeper into it i think maybe my timing chain has stretched or it's just out of time badly. i've been going round and round with swapping carbs and trying to keep the shaker hood effect on my 78 trans am with a 403. the q-jet 795cfm i had, ran great for like 7 yrs then it started to give me trouble and finally just gave out on me i had 2 people try to rebuild it and it just leaked like crazy. evrytime i removed it, there was a small puddle of gas in the intake. then i tried to use holly 600 and there it was to much trouble for me to try and make it work with the throttle linkages having to be swapped at least that is what i thought. then i currently tried to use an edelbrock 600cfm #1406 on it. and while i get it to run and acctually drove it on last sunday. it ran great. good throttle response and go from a light but topend sucked or didn't suck enough i should say, i sure missed vacum secondaries at wot. well anyway come monday i tried to start it and take it to work, the died on me after removing my foot from the pedal and i couldn't get it to start again. it smelled like it had flooded out, i tried again when i got home and she started but after putting her in drive she backfired and stumbled and then took off and then she died and i couldn't get started again. this is not the time she back fires, it happened with the q-jet a few times also. i'm gonna try one more edelbrock carb, an #1806. it's a 650cfm electric choke i hope that solves my issues. any suggestions out there.  

If it is not the carb. it could be worn lobes on the cam.  
Professional hi-performance engine builder

Horsepower sells Engines and torque wins races.

your number one problem is that edelbrock carb you got,  worthless,  I have always been a fan of the Q-jet,  I would find a junk one and take it apart and try and get used to it,  then rebuild yours,  an ideal carb for a stock 403 if you want some snort is one from a early '70s 455,  that what I used, put the stock '79 to shame.  and if the timing is off, well you cant time it until it runs.  

stick a big socket on the crank bolt... with a breaker bar... pull the distributer cap...    work the crank back and forth.. see how much play you have before the distributer starts to move... if you have more than 5/8' of movement on the outside of the balancer...  it might be time to replace the timing chain set...

the 78's did come with a plastic tooth cam gear...   gm called it a silent timing chain set..  i called it a silent motor killer...

3 piece timing chain sets are available...  and cheep...  price them around... steel gears. not the plastic gears..  regular chains will work great... or roller chains...

ask AZ for a 73007 timing chain set...  under 20 bucks...