G'day,
I believe all victa engines prior to power torque had invertible inlet manifolds that allowed the carby to he set horizontal. Im not to sure about the powetorque thought.
Aside from the carby I would not recommend that you run the disc direct on the engine because, #1 seeing as there�s only one bearing it will put so much stress on it, causing it to fail in no time, putting your 10mm piece of plate off centre - possibly with catastrophic results. #2 The powertorque has a tapered shaft with a threaded end, so there is no 'safe' way to mount the disc. Even if you welded it to the boss you would still only have 2� of weld holding it there!
Im sure you could pick up a horizontal Briggs if you looked around. The other day I could have had 2 trashed but rebuildable 2008 OHV v twins for $70! (The cost of rebuilding isn�t worth it when you have no current use).
Regards jay