Jetting on a 455

[avc1966]

The wagon has a 750 vacuum secondary holley on it. It is a 462 with Gessler stage 1 heads, poston gs118 cam, and a performer intake. Ignition is a stock HEI. It has always had a real slight hesitation right off throttle. Goes away immediately the further you get into it. I just don't have that snap with throttle response. I have 72 primary jets in it currently. Should I be headed up or down in jet sizes? I am thinking I need more fuel and it may be a sight lean condition, but not sure what jets this combo should have. Thanks for any input. Tony

[Shayne Dillinge]

A jet change will not help you for this. You need to tune your accelerator pumps. It needs a more aggressive pump cam. Try a brown one. By the way, that carb is pretty small for your combo. I'd like an 850 on there.

[avc1966]

Shayne, made a ton off difference. I bought the kit and put a brown cam in it. Hesitation is gone. Should I go more aggressive on the acc cam? Would more jetting help? Pulls hard, but curious how far to push it with a stock ignition. Thanks again Tony

[Shayne Dillinge]

Wow, that was quick. What, do you live next door to a speed shop?

I can't help you much in the jetting dept. cause my car is quite a bit different than yours. I do all my jet change tuning at the track and jet for best ET. Glad you got rid of the stumble.

[avc1966]

Was off today, and the local parts store had them, which shocked me too. Thanks for the help. I will try the trial and error method on jets to see what works. I have been driving it with this motor for almost 2 years and I'm finally tuning it in. It runs so well I just never bothered with it. Take care Tony