To help fuel in the idle areas, warm up the engine to 160 .. then I like to set the idle at 2500rpms then let it learn for a while.. then set it at 700. Let her learn...then 2400. Then 800. All the way to 1700 or whatever. Let it learn on each area. Give it 15 minutes. If it's still not close, give it 10 more. It takes time, but it will learn the idle and low rpm airflow characteristics and not die when you go for your first drive. My truck has a smaller cam so I can set the idle to as low as 400 and she'll lope along. You have to adjust the throttle for the iac to be 2-10%, but keep at her. It will learn what it needs, rather than guessing based on a generic table for "wild" cams. When you're done, set the idle where you want it on the touchscreen and adjust the idle screw so that the iac motor shows in the single digits.
Also, I'd be interested to know what your total timing is.. your tuner doesn't want you to hook up the vacuum advance? He's an idiot. Get a timing light and hold it to 3000rpms and see what your timing is. It should be in the mid 30s range. My head manufacturer recommended 36-38⁰. Your heads will vary. I've heard vortec heads like 36⁰. Your heads will vary but that will give you a general idea of where you're at. Typically more efficient chambers like less timing. . And less efficient chambers prefer more timing. LS motors are rare to see past 28⁰ or 29⁰.
Hook up your vacuum advance to full vacuum, not ported vacuum... it's any manifold vacuum in your intake manifold.. ported vacuum closes when idling and opens when your throttle opens. Just stay away from the vacuum ports on the actual throttle body and you won't mess it up.
My truck makes peak vacuum at 30 degrees of timing. It idles between 25 and 30kpa. If I get on the throttle, it shows load (increased kpa)... and the vacuum drops, lessening the spark advance. 16⁰ at idle seems awful low. You won't see a lot of vacuum with that big cam, but you should see some.. and you'll see a little spark advance from it. Vacuum advance is always good for drivability and mileage. Drag race guys are the only ones that don't hook it up. The only time you'll really advance timing with vacuum advance is when you're part throttle. Full throttle timing won't be affected so I don't know why your builder/tuner was against it.
Also, I'd be interested to know what your total timing is.. your tuner doesn't want you to hook up the vacuum advance? He's an idiot. Get a timing light and hold it to 3000rpms and see what your timing is. It should be in the mid 30s range. My head manufacturer recommended 36-38⁰. Your heads will vary. I've heard vortec heads like 36⁰. Your heads will vary but that will give you a general idea of where you're at. Typically more efficient chambers like less timing. . And less efficient chambers prefer more timing. LS motors are rare to see past 28⁰ or 29⁰.
Hook up your vacuum advance to full vacuum, not ported vacuum... it's any manifold vacuum in your intake manifold.. ported vacuum closes when idling and opens when your throttle opens. Just stay away from the vacuum ports on the actual throttle body and you won't mess it up.
My truck makes peak vacuum at 30 degrees of timing. It idles between 25 and 30kpa. If I get on the throttle, it shows load (increased kpa)... and the vacuum drops, lessening the spark advance. 16⁰ at idle seems awful low. You won't see a lot of vacuum with that big cam, but you should see some.. and you'll see a little spark advance from it. Vacuum advance is always good for drivability and mileage. Drag race guys are the only ones that don't hook it up. The only time you'll really advance timing with vacuum advance is when you're part throttle. Full throttle timing won't be affected so I don't know why your builder/tuner was against it.