My twin bravos trim at different rates... ports a tad faster. I also had milky drive oil so I just rebuilt all four rams, changed and flushed the oil from the tanks with 10w-30 oil.

The port side is still faster. Is this common? Is it a sign of a problem? Can I just put 10w-40 in the faster sides tank to slow it down a little.

This isn't a major problem, but, using the "in throttle" trim switch raises the drives uneven which is a pain in the ass.

Opinions welcome...

I replaced my port side pump motor before last season and has the same problem. I'm assuming the new pump motor is spinning a little faster. I don't know if you want to replace starboard motor, but I would bet it would take care of it. I bought motor only, from West Marine. I can't remember what I paid for it but it wasn't bad.
Just my 2 cents worth

I have the same problem - I just live with it, but it does suck that you essentiall can't use the switch on the throttle....

I would run a 5w20 in the slow one and straight 30 in the fast one.