The clutch spring bracket goes just aft and below the steering box. There's a brake line holddown clamp there and the bracket goes against the frame with the brake line hold down on top.

A few have done the TKO's. Kiesler (and others) have a kit that comes with everything you need - drive shaft, cross member, yoke, shifter in the right place, speedo gear, etc. That seems to be the way to go.