The washers I used were whatever came with the injectors.

air filter?

Not sure my brothers 12v runs about 300 deg at idle

400* is a warm idle. i set about 300-325. check the air filter check in and exiting air flow

Are you running straight exhaust or is the cat still on? If the cat is still on it might be clogged so you might try a delete pipe or a temp removal to see if this helps. What gets me is jumps high as soon as you fire the truck.

The air filter is a K&N kit, looks pretty clean. I may start it up and let it idle without the filter just to see if that would help. Exhaust is a straight pipe all the way back to the stacks, and it feels like I'm getting good flow out of both of them while the truck is running.

check you valve lash?

Hadn't even thought of that. I'll do that and see what comes of it. Thanks!

I hope thats it my next guess is cam/ lifter issue

ya thats wierd mine is at 250 at idle started when cooling down i have no problem hitting 250 again to klill the truck