123c,

You can just tighten it up with a large crescent wrench - no torque wrench needed. It has it's own flat seal washer to keep it from leaking once it's snugged up to block.

I've never seen a bushing on these things. The ones that I have seen come as one brass unit w/ a large hex nut (approx. 1 3/8" across) and male threads that fit right into the block - nothing else needed.

The cord makes a connection to the heater and you route the cord towards the front of the car tying it off to a heater hose w/ some plastic cable ties along the way.