What oil should be in my 454?
 

I have a 90' 25convincor and am getting ready to winterize it. I am wondering what oil should I be running in this, it is my first time on this boat. It has original 454 which was rebuilt about 4 years ago. Should I be running the same they run in the newer mags and mercruisers or what? Mine is a non mag just stocker 454, with mild cam and roller rockers thats it. And I have no clue what oil filter to put on it either. It has remote filter set up.

I like 20w-50 in mine but most prefer straight 30w

I have a 1990 454 Magnum with a 10qt. Canton Pan and I run 8qts. of Kendall GT-1 40w with 2 qaurts of Lucas.

I run Mobile 1 Synthetic 15w50 in mine- 1997 Merc 454/330hp. You can get it at Walmart pretty cheap, something like $23 for a 5 quart jug, you should need 8 quarts.

20-50race oil

You'll get a hundred opinions on oil to use. Use a high quality straight 40wt, or a quality 15/20-50. I run Mobil 1 15-50 synthetic and mobil 1 filters.

I was reading a mercruiser repair manual I have and it says sae40. My problem is i dont think I have ever seen straight 40 in any stores around here. One of the local boat shops told me they just put that 20-50 in every one they service, but I think they are servicing mostly newer mercruiser stuff.

yea you will get alot of different opinions, im just telling you what i have had good luck with,ive got 2 late 80s 454 bored 30over roller cam and rockers, and i run the dog out of my boat trying to keep up with the other guys, and i change my own oil, now my boat does have crossover water pipe and does run a little cooler. so weather that makes adifferent or not i also have 8quart oil pans.

mhydro4 how many hp are your motors and are they 2 bolt or 4 bolt mains