I'm putting a 350 HO crate motor in my truck. It came with a Holley 600CFM Carb. I ordered the 9/16 to 6 AN banjo fitting for the carb inlet line, but that ain't the right size. Holley is only showing 2 sizes....a 9/16 and a 7/8"...And it ain't a 7/8" either. I've figured out it's a 5/8"....Does anyone know if the elderbrock 5/8 -20 to 6 AN will work?It has to be either a 5/8-20 or a 5/8-18 and I can't find a banjo fitting that's 5/8-18Anyone know for sure?....I hate making $18 wrong guesses.Thanks

 

All the Holley side hung float bowls use a 9/16"-24 thread banjo fitting. Carter AFB and Edelbrock use 5/8"-20 thread.

What's the list number on the carb?

 

It's a GM performance part #12497147 It is a Holley 4160 single feed.It is NOT a 9/16"-24.... I ordered a banjo fitting that is a 9/16 -24 cause I thought all the Holley were that size too...They ain't.I purchased the 350 HO turnkey engine....Of course they did not include any info at all on the carb....

 

I measured the inlet nut with a tape measure. the outside dia is 3/4" and the inside dia is a 5/8"....Just not sure of the tread count.

 

I'm running the 350 HO Deluxe which includes a Holley 4160 600-cfm carb. This is the banjo I used (note that it's a 9/16-24 thread):

http://206.188.209.227/index.asp?Pag...OD&ProdID=2857

JamesC

 

If it doesn't have a list number on the choke horn then it's not a real Holley. GM could have used any float bowl. Try contacting GM and asking them.

 

I ran the p/n on http://paceperformance.com/

It's the one I'm running.

JamesC

 

http://www.jegs.com/webapp/wcs/stores/servlet/product_10001_10002_332834_-1</p>

This is the one that I bought. It is too small.

 

I bought the motor about 2 months ago. Wonder if they just recently changed the inlet size?

 

James C
Did you run the mechanical fuel pump with yours or stay with the electric fuel pump?
And are you running headers?
I'm planning on going with gibson truck headers for mine

 

I think I found my answer
Holley makes a 5/8 -18 inverted flare fitting for a 4160
http://www.holley.com/34-160.asp

 

Mechanical. Hooker 2055 headers.

JamesC

 

my 350HO seems to like a little more timing and fuel than what the manual calls for as well.

67/73 jets with a 8.5 pv.

14* initial, 34 all in. 800-3200 curve.

shes going to want some stall and some decent gears.

good luck, welcome to the HO family! haha.
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oh, I'm running 2055's and a mechanical pump as well.

 

Well, I received some more parts and pieces from Jegs today.
The fitting for the carburator is a 5/8 -18 inverted flare
The problem is nobody in the known universe makes a
banjo fitting for a 5/8 - 18 inverted flare.
If I use a 5/8 - 18 to a -06 AN and then an elbow, the
breather will not fit over it.
Why would GM do something this stupid?

 

Because they used a cheap carb list #.

 

HI! Could somebody tell me what are the stock jet sizes? my engine is running fine in most conditions (air fuel ratio 13.5:1) but at WOT AFR goes super rich 10.5:1. What should I do? change secondary jet?