[Fishjack]

I removed my Johnson 225 and replace it with my current Yamaha 250 and the holes matched fine.. I found this online for what it is worth -

"It is believed that the hole arrangement currently in use by most engine manufacturers follows these dimensions:

The top pair of holes are spaced 12 and 7/8-inch on center; each hole is 6 and 7/16-inch from the engine bracket centerline.
The bottom pair of holes are spaced 9 and 7/8-inch on center; each hole is 4 and 15/16-inch from the engine bracket centerline.
The spacing between the top and bottom pair of holes is 8-inches on center.
The centerline of the top holes is 2-inches below the top of the engine bracket. The holes in the transom should be 1 and 7/8-inch below the top of the transom. In no case should they be closer than 1 and 3/4-inch to the top of the transom. Holes located 1-7/8-inch below the top of the transom will produce a slight gap between the transom and the engine mounting bracket. This gap can be filled with an appropriate spacer or shim to help bear the engine's weight onto the transom.
When locating holes on the transom, do not assume the top of the transom is a straight or true edge. Determine the transom vertical centerline by measuring equal distances from the hull's chines. Align the engine mounting holes to the true vertical centerline of the transom, not to the top edge of the transom."

Hope that helps a little..
Jack