I've had the problem right when you punch it at cruise, let's say 50mph, kick it down and instantly the problem is there if i just catch the 2dn gear downshift at high rpm. So i really doubt it's the fuel pump, plus from WOT from 60mph to 110mph, it was FINE. I really don't seeing it being a fuel related issue, since it's instant. I'm leaning to a carb mechanical issue (like the weighted mech seccondaries closing), or ignition????