Wylie thanks again for the tip on how to tune it.

I did by ear tonight after installing the new head unit. I couldn't find my volt meter but started off under half way up on the gain and went up from there. Wow!! Those kickers on the tower are much louder now and really clear and the interior are loud and no distortion from them. I just need to grab an extra rca cable for the sub amp and it's all wired up and good to go.