Timing ?'s Here we go again.

[Mr 5 0]

Brad:

Total or maximum timing is usually 36-38 on a mildly modified engine. That means the timing at top RPM (5500) as opposed to static timing which is done at idle and should be around 14 degrees.

The large-volume headers, while great for high RPM applications, limit velocity at lower RPM's and can actually slow you down on the low end.
Smaller diameter tubes will generate higher velocity to "scavenge" or pull the spent exhaust out of the cylinder but having long-tube headers will help offset the large volume somewhat and although your ported E7's and stock cam don't really require 1 3/4" headers, if you're happy with the performance, don't worry about it.