William,
We have done many ifs swaps and after enough time even dummies pick up a few tricks. Here are a couple that doesn't require a tape measure. First BEFORE you remove the stub frame from the Nova put an angle finder on the upper A-frame shaft and get the built in anti-dive angle. This will also have your caster close in it's new home. Now tack a "T" bar onto the top of the cowl with the leg to the cowl and the (movable) cross arm above the front spindles. Drop a plumb bob on each side and adjust cross arm till string runs exactly through the center of the spindle end. Tack cross arm in place. When you put the clip in place adjust till string runs through center of spindle on the Nova spindles and your new front end is EXACTLY where your old one was. We usually tack our "T" bar to the top of the truck with two angle braces down to the cowl so when the strings are wound up everything is out of the way.

Evan