What kind of oil do you run?
 

I have a 454MAG. Been running valivone 30w. Good? Bad?

I've always run 50W Valvoline racing oil per my engine builder.

I use Merc 25-40.

mobil 1

Amsoil 20/50 series 2000 :D

Run a multi vis 20w50.
Ken

Good choose I have been using it for years with zero problems but the 40W

valvoline 40w racing

Used to run Castrol GP racing straight 40W but they discontinued it. Now I run GTX 20-50.

I run Amsoil series 2000 also.
If you are in a Northern climate and don't boat in warm water much the 30w will be fine. If you are mid to South I would only run 50w or synthetic.