Do surface drive mud motors work with both tall and short transoms without modifications?

They are built to work on one or the other.

Ok thanks, i have a 27 mb mini on a short transom, and i was looking to get a little bigger boat. I found one used but it had a tall transom. I was hoping it would work, but i guess ill keep looking.

You can change some parts on your motor to make it work, or you can have the transom cut down. I would convert the motor to a tall, but not sure how much that runs for your motor. Fixing the transom should be in the 2-400 range.

others can confirm or deny, but you may be able to get a longer outdrive (32" or 40") and accomplish the same thing by getting the prop lower. not 100% sure this would work but this way you'd always have the longer drive if you went back to short transom