Modififying the idle sytem, from Cliffs book page 93..... 17080213 carb

[GSP7]

Modifying the idle system, from Cliffs book page 93. I read through it on cliff's book with the various cam shaft scenario

Looks like this mod. is just opening up idle tube, down tube channel, etc tiny bit

Is this modification only for earlier/older carbs rather than a 17080213?

Saw a post here were some one was disguising that he did it on a '85 carb?

My engine is a sm blk chevy 350 , 9.5 :1 compression. 1970 #3932441 heads,
RV type Cam is .214/.214 dur @.050 - Lobe centers 105 in. , 115ex. , lobe seperation 110

Motor is in a k20 4x4 truck

Im about ready to reassemble the carb, clean, all checked out, , Is the above mod going to be beneficial or wont benefit and unnecessary ?

Rick

[77cruiser]

Open the idle discharge a bit too.

[Cliff Ruggles]

The 17080213 is pretty generous for idle fuel delivery.  I'd try it stock and see how it works before opening up anything in the idle system.  If you converted it to electric choke you may need some more idle bypass air.....

[GSP7]

Cliff, I am converting to electric choke and drove a lead split shot into the vacumn hole in the main body to seal it off.

I just checked the Idle bypass air holes on bottom side of base plate. A .108 (7/64) size drill bit slides in the holes.  According to page 94-95 info in your book, looks like .108 size hole plenty large

Is that .108 hole good and large enough?

[GSP7]

Edit above.

On page 29 of the book the 2nd photo up on the left side of page shows the 2 idle bypass holes locations, with the red straws inserted and crossing, where I measured @ .108


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