#1  
Old 05-20-2020, 07:30 PM
ReelFun's Avatar
ReelFun ReelFun is offline
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Join Date: Nov 2007
Location: Moncks Corner, SC
Posts: 413
Default Looking for Advice on Jets

Here is my current set up: 389 bored .30 over, 093 heads, dished Ross pistons, 68 cam, 4 speed and 3.23 ratio rear. About 9:1 CR. I live about 52 feet above sea level.

I am running a 65 tri-power. The center carb is jetted with 63 size jets currently. I am running a little rich and have played around with the A/F needles but it still runs rich. I have some 62 and 61 size jets on hand. I am thinking of using the 61's. What are your thoughts?

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1965 GTO
389 Tri-Power
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  #2  
Old 05-21-2020, 12:09 PM
Dick Boneske's Avatar
Dick Boneske Dick Boneske is offline
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Join Date: Mar 2004
Location: Winneconne, Wisconsin
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Default

You can run .061" jets with no problem if you're using ethanol-free fuel. We run .061" jets in our 434's with the same center carb. I began with .063" jets, but tried the /061" with no downside.

With E10, I don't know what would be best, but I suspect /061" would be OK. Some recommend one jet size larger for E10 than pure gasoline. I know of no basis for that, but several car friends say that.

In any case, use .070" jets in the end carbs. For the restorations I do with lumpy cams, more cubic inches, I use .073" end carb jets.

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  #3  
Old 05-21-2020, 05:48 PM
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ReelFun ReelFun is offline
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Thanks Dick. I always try to run pure gas if I can so I think I will give the 61's a try.

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