I want to know if I can use a old carbureted 350 block and put it in a 97 Yukon and strip everything off the Yukon engine will it fit the old 350 including the crank sensor

You will get the engine in, however you will not get everything eles to work such as sensors and all the other components such as lights, radio, charging system will all need to be rewire.

Sensors are the biggest thing, crank shaft & camshaft sensors, not sure if you can adapt them, Vortec engines have threaded holes in the valley for push-rod guides, as they come with roller cams so brings the issue of the cam shaft sensor. You can take everything off the 97 and bolt on the older block but like push-rods may be different lengths also. Some investigation would have to be done on these items in order for the OBDII computer to be able to run the motor.