1992 BAJA OUTLAW, WHAT OIL SHOULD I RUN 454MAG

If your asking about the oil weight i believe they call for a 20w-50 or a straight 50 oil in most boat engines. If your asking about what brand.....well thats a whole nother debate in its self!!
I personally run Red Line synthetic in all my toys. and if its got to be dyno oil then i go with Pensoil or Castrol GTX. Valvoline racing is also nice...

Religion, Politics and Oil type are three things that should never be discussed on an internet board

There are lots of oil discusion threads, do a search

I just sold a 1991 Baja with twin 454`s. Bought it new. Always ran straight 40 wt and changed EVERY 20 hrs.

It gave me 760 hrs of great service and still runs like new.

40 w Redline here.

LOL

I was told to run SAE30 or SAE40 and that's what I have done for a few years. Change it every 20 hours. I just switched to a synthetic to see if I could actually see a difference(oil pressure, temps, etc)

The brand is up to you, everyone has different opinions. I ran Valvoline.

Mercruiser owners manual states use straight 40 weight oil.

I personally run Castrol GT High perf racing oil. 460 hours of which 160 include a Whipplecharger. Still same oil presssures as the day I brought it home from the dealer.

Just remember whatever oil you use MAKE SURE the oil is fully warmed up before you start running it hard. This is the number 1 cause of early wearout of motor parts.

Bigwavz is right. Using a thick single viscosity oil requires plent of warm up before you hammer it.