New T stat & new radiator

I installed the new gaskets today.  New carb base gaskets and intake manifold gaskets.  My problem is exactly the same as it was before.  The only thing left is the carburetor now.  The carb must be responsible for the air/fuel problem.  What should I do now?  
1969 GTO, YS code 400, 350hp/445 ft lbs of torque (stock specs), LT headers, H-pipe, 750 Holley 4160, Ignitor II ignition.  Complete Painless wiring.

Are you talking about the hesitation problem if so.
Did you ever check the accelerator pump adjustment.  
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The car hesitates when I accelerate.  The vacuum needle vibrates rapidly and jumps up and down at idle.

What is the accelerator pump adjustment?  
1969 GTO, YS code 400, 350hp/445 ft lbs of torque (stock specs), LT headers, H-pipe, 750 Holley 4160, Ignitor II ignition.  Complete Painless wiring.

Well on a holley it is on the front driver side corner and has a nut and bolt that is spring loaded tightening the nut and bolt gives more clearance loosening the nut and bolt give less clearance.  
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I have determined that the 2 year old 4175 Holley carb needs rebuilt.  It dumps raw fuel into the engine.  I suppose the repeated attempts at starting the engine over the years, and the constant sitting with old gas for long periods of time took its toll on the new carb.  I took the car to a local shop that works on old cars and they confirmed that the carb needs rebuilt; however they told me they couldn't do it because they're too busy and the guy that rebuilds carbs is "no where to be found" (terrible customer service).  Very frustrating.  So now, I need to either rebuild the carb myself, or buy a new one.  I am not familiar with carbs but I suppose I could give it a shot.  
1969 GTO, YS code 400, 350hp/445 ft lbs of torque (stock specs), LT headers, H-pipe, 750 Holley 4160, Ignitor II ignition.  Complete Painless wiring.

Ya That will ruin a carburetor.
Don't sweat it Holley's are not too difficult to rebuild.  
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Okay, I'll try to rebuild it myself.  Do I need a "renew" kit with gaskets and seals, or do I need the full "rebuild" kit with gaskets, seals, needles, jets etc...  It's my understanding that this is a fairly new carb that only suffers from damaged gaskets from sitting with fuel for so long.  I think fresh gaskets should be all the carb needs, but I really don't know.  
1969 GTO, YS code 400, 350hp/445 ft lbs of torque (stock specs), LT headers, H-pipe, 750 Holley 4160, Ignitor II ignition.  Complete Painless wiring.

Gaskets,seals, needles and seats as well as accelerator pumps and power valve or valves.  
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I am kind of sweating it.  I have no experience with carburetors, and very few sources of help.  It can be pretty intimidating.  I am considering buying another carb.  That way I can always have 2, one as a back up that I can have ready to swap on.  I have a spread bore 650cfm Holley 4175 now, I know there are better carbs.  What is a really good carb for making high performance and high torque?  It's got to be something that is fairly easy to tune and deal with.  And, I suppose I could use an adapter plate to further increase my options of carbs.

Should I by a cheap one to get it on the road while I get the other one rebuilt, or should I get a really nice one...?  
1969 GTO, YS code 400, 350hp/445 ft lbs of torque (stock specs), LT headers, H-pipe, 750 Holley 4160, Ignitor II ignition.  Complete Painless wiring.

I purchased an electric choke holley 770 street avenger from summit.  Its on my wt 400.  This replaced my ailing 750, which had some of the symptoms you describe.  I couldnt be happier!  The primary, and secondary jets are exactly what my engine needed.  Plugs are perfect now!  I needed to bump up the accelerator pump shot (white cam), and increase the size of the squirter nozzels to #30.  I also, lightened the vac secondary springs to white (these come with the carb).  Now, it starts perfect hot or cold.  No more erratic idle.  Immediate throttle response from a stop or while crusing.

The DVD Holley sends is excellent.  My car has a mild cam, Edelbrock pontiac performer intake, 1/2 spacer.  16x heads with stock duals, and is an auto.

Hope this helps

Rich  

That's exactly what I want my car to be like!  Mine is a stock motor with rebuilt #13 heads, long tube headers, and a 2.5" H pipe without mufflers.  I figure around 750 cfm should be sufficient.  I wonder if I could get the same results as you with a Holley 4160 740cfm, only because the 770 you mention costs a fortune (to me haha).  And if I go with a square bore I'll want to by a performer intake to mount it, and I'll just run an adapter plate for a while.  
1969 GTO, YS code 400, 350hp/445 ft lbs of torque (stock specs), LT headers, H-pipe, 750 Holley 4160, Ignitor II ignition.  Complete Painless wiring.

The Holley 750CFM vacuum secondary carb. like the 3310 would be fine for your setup.
I have used them and they work great.  
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$290 bucks vs. $750.  I'll take the Holley 750 4160 vac secondaries square bore carb!  Can't wait to get it!!  
1969 GTO, YS code 400, 350hp/445 ft lbs of torque (stock specs), LT headers, H-pipe, 750 Holley 4160, Ignitor II ignition.  Complete Painless wiring.

Shortly I will be ordering a Holley 750 4160 carb, a spread bore/square bore adapter plate (until I get a performer manifold), a 14" X 4" chrome air cleaner, and a sun pro super tach II (since my dash is out).  I am going to be all set!!  
1969 GTO, YS code 400, 350hp/445 ft lbs of torque (stock specs), LT headers, H-pipe, 750 Holley 4160, Ignitor II ignition.  Complete Painless wiring.

Yep.  
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