Will an intake from a 93 350 throttle body chev fit on a 99 7.4l vortec block?

No, a throttle body intake from a 1993 Chevrolet 350 will not fit directly onto a 1999 7.4L Vortec block. The 7.4L Vortec has a different bolt pattern and design, as it is part of a different engine family with a more advanced intake manifold system. Additionally, the Vortec engines typically use a different style of fuel injection and require specific intake manifolds designed for their configuration. Thus, modifications or an adapter may be necessary for compatibility.