if i bought a o.s. .18 tz (p) turbo with 11k slide carb could i still use my stock stuff from the vertex

You need to make sure the motor you purchase has a thredded crank for your clutch and flywheel to work properly. It can be done on a SG crank but is a little more involved to get the correct offset spacing you would need on the flywheel and clutch. You will also need to make sure you get a motor that is a small block with side exhause. The carb that comes with the motor you will have to play with the throttle linkage a little bit as well...