I have 55 bird stock 292 automatic, mummert intake, 415 Holley,Petronix ignition,MSD box and coil. Taylor wires,new plugs gapped properly. Ford Powertrain Headers. I took the bird out for a performance check ride today and all was well. Cruises like a new car and everything was in limits and working as it should . Until I got home. After about 30 minute drive I pulled into driveway and slowed while the garage door opened and car started to stumble while at idle . It eventually stalled. Tried to start car ,nothing. It usually restarts easily if started right away. Not this time. Tried 2 times . Held foot to floor and after about 10 seconds it fired up and acted up stumbled and stalled . Re-start was as bad as the first. Finally got it inside and began to inspect .  I removed float bowl check port for fuel level. Could not tell how much was in there but the float was bouncing up and down as I pushed it. Operated throttle by hand and fuel came out in a good stream on both sides . A few minor leaks from loose screws and nothing more. I didnt notice till today that my vacuum line is connected to a vacuum port on the passenger side of the carb. I am not so sure thats the correct place. When the car does run it runs great on the road and as it gets warm/er it starts to stumble. Idle speed is set at 700-800 RPM. Couldnt find anything outstanding so i drove it again and this time I help the accelerator down a bit to help it keep running. As I pulled into garage it stalled again. Engine temp was  around 170. So, I ask do I need my phillips or common screwdriver to start with? As always your assistance is appreciated . Earl Dagenhart   

 Earl, have you thought of removing your garage door so you dont have to stop and no problem? Ha, Ha.  Holleys often have flooding problems due to sticking needle/seats, perhaps reset float levels.

Those are my thoughts. It seems that every thread here about this issue everyone has parts to replace,adjustments to make etc. All the time I have had Holley carbs on it I have had hard starting issues. This carb was rebuilt by a company in Galveston Texas with a 2 yr warranty. Unfortunately the warranty is gone but still hard starts and stumbling . I hate to spend money for a new carb but spending money on parts for the one I have may be the wrong road. I have the carb sitting on an aluminum spacer . Should that be addressed first?  BTW I would never shoot a Bird owner.  

Assuming both float levels are fine, then try cleaning the eight air bleeds located at the front of the primary venturies and at the rear of the secondary venturies.  Use carb cleaner with a nozzle to force feed the cleaning solution into each air bleed hole.  Upon recranking the engine, reset the idle mixture screws for best idle or best manifold vacuum.  Baseline for this should be 1½ turns out for each adjustment screw and then adjust both in and out from there.  When you're said and done, both screws should be adjusted approximately the same.

Another possibility is a ruptured power valve.  Letting the engine sit for a few hours and then checking the fuel level in the primary fuel bowl to insure that the level are staying up is a good indicator that the power valve itself is okay.

What’s the list number on the carb you’re using?

       Pull the carb, and fill it with fuel. In a vented area (you knew that). Watch to see where the fuel is coming from. Could be a Metering plate gasket, or most likely, it'd be a ruptured power valve as Ted said. That's pretty common on holleys and those are the symptoms.

   Holley has had a number of QC issues lately, including warped metering blocks. The die caster was not checking the parts and pulling them from the die while they were too hot. They can warp or bend in that condition.  

thought pictures may help. 2nd one shows gas leak at back bowl. Most likely from sight hole. 

Aside from the other good suggestions I read above - put steel needle and seat assemblies in there. Hoosier convinced me after I found the sticking needle seat problem more than once. 

Get a thermal isolator spacer - it will lower the body / throttle plate temp of the carb a considerable amount. 

Have a fun weekend

does fuel run out of that bowl if you pull the plug?

   From the pixs of your Holley I believe you have a 4150. The clue is the rear metering block on the 4150 vs the metering plate (thin with fixed jets) on the 4160. And see, a 600CFM is not too big for a good running Yblock.

Another item to check while you’re on the inside of the carb is the power valve gasket.  This gasket being improperly installed or being the inappropriate gasket for the particular power valve being used can also cause problems with fuel leakage past the power valve.

TED the carb is an older 4150 no adjusting screws. None of the parts places heer go back that far and none have Holley kits. Back to square one I guess. Thanks for all the information. It is priceless to me. 

If going for a new carb, The list #1848-1 (465 cfm) Holley carb would be a suitable choice.  It’s a good all around driver on a either a dead stock or mildly hopped up Y engine.  From an appearance point of view it looks like an original carb.  Be sure to shop around though as pricing varies considerably on this carb.  Summit or Jegs will come close to having the best pricing for this carb.