replacement idle tubes question?

[slicer87]

 I was wondering if the replacement idle tubes you sell need to be drilled to to the correct size. If they do how do you hold them for drilling?

[Cliff Ruggles]

Unless requested, we leave them at .034".

They are drilled by hand with a pin vise, no need to hold them with anything more than your fingers.....Cliff

[slicer87]

Okay. My SBC 305 has headers and a aftermarket cam that has 270/276 advance duration, .440/.454 gross lift, and a 1600/5400 RPM range.  

CamTiming: TAPPET @.050
Lift:                   Opens           Closes           Max Lift    Duration
             Intake  (4) ATDC         34 ABDC     109           210  
          Exhaust  47  BBDC       (11) BTDC     119          216  

Would you recommend enlarging the idle tubes from the stock size?

[Cliff Ruggles]

What is the carburetor number?

Upper idle airbleeds?

Lower idle airbleeds?

Idle downchannel?

Idle bypass air?

thanks....Cliff

[slicer87]

 Carb number is 17086003 0356JMX, don't know the sizes of the other stuff since I haven't taken the carb apart. The main air bleeds in the air horn are unbushed. 

[Cliff Ruggles]

Appears to be a later computer controlled unit.  They are excellent carburetors, and the only thing the ECM controls is part throttle fuel.

They still respond well to high performance modifications, and have an adjustable upper idle airbleed system. 

We sell complete HP kits for them, and tuning parts as well.....Cliff