I'd go with Scott. The upper hsg. gear shim tools give you cone point match and correct backlash. I suppose you could blue the gears up and get a good match pattern, then figure out how to adjust the shims for the correct backlash, whatever that is, and however you'd measure it.
But the backlash is important. Those gear teeth bend under load and need that clearance to avoid unwanted contact and interference. The lower prop shaft hsg uses a shim tool for cone point, and an involved process to check the .017"-.028" backlash.
That top gear set runs at WOT speed of 4600-4800 rpm. There isn't much room for error.