Crazy unequal length header build for '88 Ram50 !!!

[SubGothius]

With the idle speed screw 1-1/2 turns in or less, a mixture screw anywhere from 1-1/2 to 2-1/2 turns out indicates your idle jets are correct. If it runs better with the mixture any less than 1-1/2 turns out, the primary idle jet is too rich, or more than 2-1/2 turns out, it's too lean.

That said, sooty plugs suggests a rich condition, so you'll prolly need to tune your primary main and/or air jets. Main jets are big steps in tuning the mixture, and air jets are for fine tuning within those big steps; larger mains are richer, while larger airs are leaner -- i.e., when swapping to a smaller (leaner) main jet, also swap to the smallest (richest) air jet you've got and increment up from there to fine-tune it leaner, or going to a larger (richer) main jet should also start with the largest (leanest) air jet you've got and increment down to fine-tune it richer. From the sound of things, you might just try swapping your primary and secondary main jets, and put your smallest air on the primary and largest air on the secondary.

BTW, did you plug the PCV barb(s) on the valve cover? Or the EGR on the intake manifold? If it's the PCV, you should at least have the PCV valve at the front of the cover connected to the hose barb in the manifold right at the carb mounting flange. The rear barb on the valve cover can be plugged or capped with a breather filter; I like the Spectre 3995 for its durable low-maintenance stainless-mesh filter media, which is fine for this vent that really only ever purges vapor from the crankcase and doesn't intake anything.

[Boogiefab]

With the idle speed screw 1-1/2 turns in or less, a mixture screw anywhere from 1-1/2 to 2-1/2 turns out indicates your idle jets are correct. If it runs better with the mixture any less than 1-1/2 turns out, the primary idle jet is too rich, or more than 2-1/2 turns out, it's too lean.

That said, sooty plugs suggests a rich condition, so you'll prolly need to tune your primary main and/or air jets. Main jets are big steps in tuning the mixture, and air jets are for fine tuning within those big steps; larger mains are richer, while larger airs are leaner -- i.e., when swapping to a smaller (leaner) main jet, also swap to the smallest (richest) air jet you've got and increment up from there to fine-tune it leaner, or going to a larger (richer) main jet should also start with the largest (leanest) air jet you've got and increment down to fine-tune it richer. From the sound of things, you might just try swapping your primary and secondary main jets, and put your smallest air on the primary and largest air on the secondary.

BTW, did you plug the PCV barb(s) on the valve cover? Or the EGR on the intake manifold? If it's the PCV, you should at least have the PCV valve at the front of the cover connected to the hose barb in the manifold right at the carb mounting flange. The rear barb on the valve cover can be plugged or capped with a breather filter; I like the Spectre 3995 for its durable low-maintenance stainless-mesh filter media, which is fine for this vent that really only ever purges vapor from the crankcase and doesn't intake anything.

I do have the pcv hooked up now, I had it plugged earlier.

I appreciate the in depth explanation.

For reference, I'm in Pennsylvania, at an altitude of about 400'.

I'm only starting on lean best idle tuning and haven't driven the truck yet. Do the main and air jets matter this early in tuning the carb? Basically, should I wait until the truck is driving to get into the main and air jets?

[Boogiefab]

Link to the (mostly) finished truck

https://youtu.be/FQrYYG2XxNY