When mating an alien engine and box using an adaptor plate, usually you use the pressure plate that fits the flywheel, and the friction plate that suits the gearbox spline count.

If the friction plate you want to use is smaller than the one that would have been on the engine originally, obviously it wont grip as well, but are there any other ill effects?

How much of a size difference can you get away with? (is dropping to 228 from 240 ok?)