How to ID a 90 bottom end with a 110 top end

[KI4UJO]

I used the search bar to no avail, so I now need to ask: How do I identify a 90 motor with a 110 top end? I am going to look at a parts unit saturday that was once owned by a racer, and has various items such as a hondaline hitch. Looking at the photos, it is possible that it has this combination for a motor. If you all could tell me what to look for, that would be great.
Thanks in advance

[shortline10]

If it was indeed a 90 bottom end with a 110 top end the crank would have to be replaced with either a long rod 90 stroker crank or a stock atc110 crank , the atc110s stroke is about 3/8" longer than a atc90 . Also the case bore is 1mm smaller on the atc90 so it would have to be bored to accept a atc110 cylinder . Check the serial # on the case and the cc size on the cylinder and you will know .

[KI4UJO]

I know for sure that the cylinder is a 110 unit, but not sure on case numbers. Where would I find them, and what would the correct numbers for a 90 case be?

[MonroeMike]

http://www.3wheelerworld.com/showthread.php/141286-Honda-Engine-Serial-Numbers

[Vealmonkey]

If you know for sure it's a 110 top end, then why worry about what the bottom end is? It just doesn't make sense.

[KI4UJO]

I just thought it would be neat to have a modded motor.