clutch issues?

Okay... Now that I know the head gasket replacement was successful, I decided to see how much get up and go this pony has. When I shifted from first to second and stepped on the gas, it seemed like there was some hesitation and then I felt the power. Could this be a sign of the clutch slipping? If so, how could I test the clutch to verify it is working okay? If it is bad, how much effort/time/cost am I looking at in replacing it?

Thanks again,
Bighead