Old 09-20-2010, 05:33 PM
  #1  
bp1x71
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Join Date: Sep 2010
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Default 357 small block chevy carb problems with vacuum

I have a 357 small block chevy motor in my race car it has dart pro 1 alum heads srp dome pistons.... runs 6.6's to 6.8's depending on weather. but anyways i have a queston about the carburator. it has a proform 850 4 circuit idle screws the center section 850 holley. the rear vacuum port has to remain open for the car to run those numbers and to idle right. if i put the plug on the port and turn the idle screw way up the car will run 8.20s and backfire going down the track. i believe that has some to do with consistency. it also has 80 squared jets. i was wondering if someone else has had this problem if so please help thanks alot this is my first year racing and i would love to win a race before the season is over
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