Another Holley jet question.

[Don K]

I'm making progress on my 67 Barracuda and it's time to rebuild the carb. I have a Holley 4165 650 cfm. I'm putting it on a 74 360. The engine is a mild build 30 over 9:1 compression stock heads mild cam what we used to call an RV cam, I don't recall the specs. And headers. I will be running a 4 speed. I live at 4700 feet elevation. Just street use no racing. As I'm tearing apart the carb and I noticed it has size 58 jets, that seems a little small to me, I was thinking 64. The power valve is a 7.5 that is in the kit if that makes a difference. Any suggestion on jet size?
Thank you.

 

[Ricks70Duster340]

I'm making progress on my 67 Barracuda and it's time to rebuild the carb. I have a Holley 4165 650 cfm. I'm putting it on a 74 360. The engine is a mild build 30 over 9:1 compression stock heads mild cam what we used to call an RV cam, I don't recall the specs. And headers. I will be running a 4 speed. I live at 4700 feet elevation. Just street use no racing. As I'm tearing apart the carb and I noticed it has size 58 jets, that seems a little small to me, I was thinking 64. The power valve is a 7.5 that is in the kit if that makes a difference. Any suggestion on jet size?
Thank you.

No one can really help with recommending a size because every situation is different. Run the carb as is and tune it for what the engine needs!

 

[AJ/FormS]

At sealevel you might be looking at Primary MJs of 66/68s. allowing two numbers per 1000 ft is 58s.
The Secondary side could be about 6 to 8 numbers bigger.
But If I was working on that beast, I would probably start with a 10.5PV; it will roll into the power so much nicer.
You might as well assemble a small collection of tuning parts cuz at 4700 ft you'll probably need them.
But like the previous poster sorta says; run whatcha brung.

 

[crackedback]

look up stock jetting and start there

4165 is a spread bore so the jet size doesn't sound too far off.