SWAP UL cylinders for ULS

I did one this year.  Turned the top of the ULS cylinder down to fit the heads.  Reassembled and jetted the carbs.  Easy swap.  Not recommended I know but I have had no problems with the engine.  

Sorry, indeed forgot to mention that the gear needs replacing. Bill made a very valid point there, of course.

Some big bore kits require machining. This swap does not.

What “Gear” did you mean needs replacing?

Look through every page of the IPC (Part Catalog) in detail !!!  *** <---<<< ***

The UL had "Narrow" Gears.
The Gears were widened in the ULS to accommodate the increased Power.
You might also have the Narrow Dog Hub/Gear.
Also, Confirm whether you have the 2.43:1 or the lower power 2.27:1 Gear set.

There are other issues as well that YOU will need to address.
This is not a project recommended for the inexperienced.

I agree with Bill. You may have some serious issues coming and it may be in flight.