how to hook it up on a OFFY manifold i have the heat plate

What plate do you have?

What engine is this?

What exhaust are you running?

i have langdons Inlet Manifold Heat Plate its a 230 Stovebolt Cast Iron Headers

Do those headers have the threaded bungs in them (kinda look like O2 sensor bungs)? If so that's where (if not, you'll have to come up with your own source, see if there is a cast in boss for a hole, before you drill).