first time down the track advise?

I know this sounds dumb..but do you have a hood scoop on the car? When my Son and I first ran our Vega it would run good till half track and then would buck and snort like it was running out of fuel. Long story short we hadn't sealed the hood to the carb and at speed the air rushing past the carb would siphon the fuel out of the secondaries. We taped a temp card board seal on it and solved the problem.Not likely in your case but just something to think about.