390 jetting advice needed

Ok I got it running fair today. Here is the scenario:
1978 390 or. New engine. 38 vm carb. 40:1 golden spectro with 92 e0 premium. Tried procircuit recommendations, way to rich, I think. Here is where I am with jets at this point.
Main 390
Jet needle 6f15 clip 4th from top
Needle jet Q-8
Pilot 45
Airjet 2.0
Air screw 2 turns
These are the symptoms. Idle screw must be turned in almost all the way till the spring coil binds.
It will idle though. The slide is about 1/4" up on the back side. This can't be right can it?
When riding it is blubbery from 1/4 to 1/2 throttle until the rpm's pick up then cleans up and runs pretty good. I am getting a handle on how the pilot jet and air jet work but the needle jet has me confused about where to go next. Seems like still too rich. I have a p8 which came out if an it465, maybe i will try that next.
Thanks in advance for any clues provided.
geary

Do you still have the stock 2.0 slide? That was too rich. It needs to be at least 2.5, and maybe a 3.0 depending on your altitude.
Until that's done it's not gonna jet right. After that, you should be able to start dialing it in. What's your altitude?

I forgot that. Home is 1700', usually ride around 2000'. The 2.5 slide I can't get till next weekend. Maybe I will order a 3.0 too.

Another option is to borrow a 3.0 and just grind yours to match. Then you'll have a 2.5 and 3.0 to play with. I'm thinking you'll end up at 3.0.
For now, put the clip in the middle, open the air screw to 2.5, and that will help a little. It's still gonna blubber till you do the slide. DON'T use the P-8!

I took the old beat up slide and ground 1mm or so off. Moved the clip to the middle. WHAT A DIFFERENCE!!!
I was able to turn the idle screw out 3 turns and it idles good now. Thanks you Picklito for the help!!!
I rode up and down a gravel road and runs pretty good. I just brought it back and put it in neutral and when I let the clutch out I hear c clacking sound coming from the clutch. if you pull the clutch handle a little it goes away. Guess I better pull that off next.

Didn't we have the slide "talk" in my garage? I knew you weren't paying attention, just lost a whole grade.

Awesome!! But I'd still recommend borrowing a 3.0 to compare yours to. They actually aren't mm increments and if you've ground away too much you could discover some lean spots. So put that on your list, get a reference 3.0, and verify!!

Ooohhhh.....stabbed in the heart. I was payin attention, honest, I just didn't want to grind on my only slide. I robbed one from a yz and ground on it. I'm going to order some more stuff soon. The q8 needle jet i got from DCVMX was short version so I had to use the physically bigger main instead of the small one with the collar. the only jet like that i have is a 390. I need to make sure I get the longer version next time so I can use the other mains I have. Progress is being made and that is the main thing. My brother might run it at the hillclimb on the 29th. We'll see.

Oooooh... busted by Teacher!