What is the diffrence between the vortec 350 and the chevy 350 can you put a vortec in a older truck that had a 350tbi (1994)

You need to check the ports and plane of the intake manifold. The only real difference between the early model 350's and the vortecs are the heads. We have run dirt cars for years and as good old style heads became harder to find we started running vortec heads on the older model engines. You should be able to make that swap, but will need to check the plane (where the head and intake attach) to make sure those angles match up or your result will be a significant air leak.