car still diseling run on prob

I have a new 4.5 you are welcome to have if you want to try that.

Your timing sounds about right on. The higher timing should give you better
air fuel mix with a high lift long duro cam, that's why they need more initial
to smooth things out. Did you hook a vacuum gauge up to make sure 18
is about right for the cam? In other words, hook up a vacuum gauge and keep
advancing your timing, keeping your idle rpms constant until you reach max
vacuum reading then back off one degree. That's a great place to start for
timing and should be great unless it's over 20 and then you might start to
get starter kickback in which case you can lower it back down.