Changing motors

I currently run a 1990 150 Evinrude. Looking at upgrading to a newer motor and it is a mercury 150. My question is will the mounting holes line up on the transom? I am pretty sure that if they don't, a small jack plate may work to be able to use the same holes I would think.

Mounting holes are the same, nothing else is.

Don't know if you've considered it but if you're truly going to upgrade do it right and go 4 stroke. I've had'em all and nothing compares to a 4 stroke for dependability, quietness and economy. Like having a car engine on a boat.