Hey guys, I am wanting to update the engine in my '71 220, to get a bit more power out of it and preferably convert it to a manual in the process. So a couple of questions:

1. Is it better to work on its current engine or replace it with an engine out of a newer merc?

2. If I am to replace it with a newer engine is there any suggestions on which engines i should be looking at?

3. Is this something that has been done before?

Help with this would be much appreciated

Thanks