Acceleration problems

what is the reason most cars lose their "pickup?"when you step on the gas,you can here the engine revving higher,but doesn't grab until a second later?

Traction....

Not all engines are the same.

Some make a lot of tourqe and that doesnt happen.

the clutch could be slipping and takes a second to grab. or your engine could be bogging because of too much fuel in the low RPMS

All cars in general? or is this a specific problem on your 3000 GT?

Could be your throttle
Becuase you are pushing it to the limit and puttin it to the floor you could just be overloading the engine.