35 mph WOT power loss

We call that edelbog... (mostly kidding)
You're running an Edelbrock carb, right?

I'd check that the accelerator pump is working correctly and then maybe try increasing the pump shot to see if it helps the hesitation. It's also possible the step up springs or whatever controls the secondaries on your carb is reacting too slow.

If it's not an Edelbrock carb, ignore everything I just said! LOL