is my cam to big for the heads i have

I think it will have plenty of power that will last well beyond 5500. You'll be fine.

I have taken a STOCK 318 with a 4 barrel and headers to 6K plus and it was still pullin. Those cams were typically in the 190s for duration @ .050".

I think some of yall miss the point that a cam with a duration of 220 @ .050 might be "mild" but it's THIRTY FRIKKIN DEGREES BIGGER than a stock cam. That's a huge jump.

The stock 340 cam was in the 220 @ .050 neighborhood and those would pull to seven grand. Long as you use the right valve springs, nothing's gonna lay down up high, power won't fall off, it will be fine. You keep goin up in duration and I can guarantee one thing......you will LOSE some bottom end torque and I don't think you want that.

Cams are like carburetors. Err on the small side and you will always be happier.