subject says it all. i have a 2bbl Holley 500cfm on my 258. as you can imagine, its running alittle (alot) rich. need to take the jets down some and i am wondering where to start. any hints on what a 258 would need as far a jetting goes? thanks! matt
The 500 cfm carb is meant for circle track racing. I would go with the 350 cfm two barrel. The smaller carb will be much easier to jet. Even a high revving 258 will never need 500 cfm. You will never be able to achieve proper fuel metering with that carb. But to answer your question: I believe the 500 comes with nubmer 73 jets.
nenofury, you are right on! the carb is a left-over from my circle-track days. i bought the carb new from summit, threw it on, adjusted the float and idle mix, and went racin! never had a problem on the SBC 355. after selling the car, i had two extra holley 2300's. both almost new, stock jetting. so, for fun i thought i'd try putting one on a 258. it made a world of difference! so, i put the other one on my other 258 and made the same difference. now that summer is here, i want to drive the jeep more. only problem is i don't want to smell like rich exhaust all day. so, i just need a place to start with the jets. if i knew what they 2300's come with, i'll make sure not to get anything bigger. i will do the final tuning with the O2 sensor and a volt-meter. thanks! matt
While it doesn't answer your question, I purchased a new 350 cfm and it came with 61's. I since dropped to 59's and just a couple of weeks ago dropped again to 57's. Still happy with performance. With the 61 & 59s, guys following said I had considerable amount of black smoke when accelerating. Not so since I went with the 57's. John
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