I am wondering if any of you that are knowledgable with 383 HP motors have ever used a Comp Cam #21-304-4. Gross vavle lift .464/.464, tappet lift 268/268. I had my motor professionaly rebuilt last year and am messing around with tuning. I told them I wanted a slightly lumpy sound(which it does) and a little more aggressive than stock profile(not sure about this). My question is that when I set the timing at 5 degrees initial with advance plugged(like my other Road Runner), it stumbles with no power. I should mention that I converted to the Mopar electronic ignition with orange box. I then set the timing per the electronic kit instructions, which has you advance the timing at higher rpm's. The car now runs excellent- 10X more power-easily smokes the tires in 2 gears with 323's in the rear. No pinging at all and starts good. Now when I check the initial timing it is set at 21 degrees. I have never heard of anybody with this much. Should I be worried it is so high? I am curious if the cam I have is causing this?