RE: Welcome to Club SAITO !
With some of the Saito's with the carb not in the center of the rear....
When you turn the engine on its side with the same thrust line, the carb is still the same height.
With the centered carb, when you mount the engine on its side, the carb will be lower and you will need to lower the tank.
This carb to the side deal is also on the 91S engine and they came out in the mide 90's. So its been around a while.