AFB jet problems - 1967 Chrysler 300 with AFB 4326S

judgeholden

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First time post here, so hello. I recently purchased a 1967 Chrysler 300 with a 440. It's amazing but needs a lot of TLC. I tore apart the Carter AFB (it's stamped "66 4326S"). Hard to tell if it is the original, though the manual says that this is the correct carb for a manual (mine is an automatic). Regardless, it was a hot mess, full of junk and rust, and desperately needed a rebuild. Unfortunately, I could not remove the jets without damaging them. After doing so, I noticed that the primary jets were NOT the same type that are easily purchasable for AFBs. They are taller, so the more common style (which is used in the secondary) will sit further down. The jets, per the manual, are .098 and .077. Anyway, I guess I have a few questions.

1. Can i simply use the shorter style without greatly affecting performance? Logic would say that it "step up" earlier than normally, possibly causing it to run excessively rich. Would a softer spring compensate for this?
2. If I cannot, how can I use the newer style? Some research leads me to believe I will need new (shorter) step up rods (and maybe springs) along with the flat style step up rod covers (mine are the "dimpled") along with the new jets.
3. Would it make the most sense to just change it all out regardless? Any advice on rods/jets/springs for added performance and/or to compensate for the changing quality of modern gas?

Thanks in advance for any feedback :)
 
There's only ONE length of AFB primary metering rod. Worry more about the hole in the jet than the "edge" around that. As long as there is fuel in the bowl at the spec height, that minor edge height should be of NO significance.

I have a '67 Newport 383 4bbl, with a similar AFB. Against cautions to not cross-breed jets and rods, between AFB and AVS (which are 3-step rods), I could tell no difference between any of them (of similar diameters). So, if you want to purchase the "Rod and Jet Kit" from Summit, go ahead. Otherwise, just clean out what you have, match the jets with the factory service manual, similar with the rods (although you'll need the decode sheet in the jet kit for this), and take it from there. Stock springs should be fine, too.

That the carb is allegedly for a manual transmission is of little significance, as to jetting and such. Might be a tad on the lean side, but not by much and not across the board.

Just some thoughts and experiences,
CBODY67
 
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