tube size

[cadfor]

I'm planing on building a set of lakes style headers for the 472 I'm putting in my car. I've read in this form that 1 5/8 is a good primary tube size. The flange set up that I got from here is 1 3/4. The tube length on the lakes style will aslo be farely short, 6" on the front cylinders going up to 9 for the rear tubes. Question is do you thing the larger tube size, short run that it is, will it hurt the motors performance?
It's a 472, 30 over, 950 heads with larger valves,pocket portered, MT5 cam, Edlbrock intake with a 800 carb.
Thanks for your help