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I have an old '71 Dodge D100, 3.91 gears, Mazzolini tranny w/2400 converter and a small block that won't run. It pops and farts and bucks and snorts. I have moved the timing, I have changed power valves in the Holley 670 street avenger from 2.5 up to 9.5. With the 9.5 it will at least shift into second without dying. I think I went way too lean but the more gas I give it the better it runs but dang I am putting a lot of fuel through it (77 mains) and it still pops through the carb and runs crappy and doesn't seem to have a lot of power, although I can feel her like she wants to run but just can't. I am severely hearing impaired so I can't hear pinging.
The more power valve I put in it, the less idle screw I need for a loopy idle. I am about 1/2 turn out but that is where my vacuum is the best (16) and my idle is about 1000 rpm. Idle vacuum in gear is a little over 11. The motor I built from many parts laying around (new parts). 318 +.060 (it runs very cool temp wise), stock compression for todays awful gas. Cam is Mopar .450/.455 lift, advertised 268/272 duration, @ .050 is 228/231. Biggest baddest heads Mopar made (6-pac castings) but with the 1.88 int. I port matched to a Weiand Stealth. Tight tuck style headers, very open exh, with Purple Hornies for muffs. Perfomance Dist. unit with the brain on the outside of the dist. and coil also on outside, I think it is a Tri Power unit. It has internally 22 degrees that comes in at 3000 rpm. And of course that damned Holley. Not a single person has said anything good about Holley and maybe I should have got the Edelbrock carb. If you can think of anything I may have missed I would be greatful. After assemblying the motor it turn over so smooth with between 40 and 45 foot pounds of torque on the wrench. I am thinking of naming it the Buckin Fuzzard. Thanks ahead of time for any direction you may provide. Thanks.
It sounds to me like you may have a fuel delivery problem not necessarily a carburetor problem. I personally prefer tuning a Holley over a Edelbrock any day. You need to hook up a fuel pressure gauge and make sure you are seeing at least 6 psi, minumum. You did'nt specify whether you have an electric or mechanical pump but I would suspect a pump issue, regulator issue, or fuel line issue. These types of problems can be a real pain to diagnose but I KNOW the first step is to ALWAYS have a fuel pressure gauge connected. Hope this helps.