Doing a first oil change on a new to me 1969 35 Commander Sport Cruiser. It has Model 270 Crusaders. I am in Maryland and am looking for what weight oil and should I use conventional or synthetic. Also with this being a marine engine do I need to use any type of oil additive? Also what are the go to oil filters?
Thank you in advance!
270 Crusaders would be conventional flywheel aft 350s and not the CC 350Qs. A high ZDDP oil like Valvoline VR 1 in either 30wt or 10w30 is preferred for flat tappet engines. With the temps in Maryland, you can probably stick with a single viscosity oil. Driven GP-1 is another great marine oil with high ZDDP and is available in several multi-viscosity options.
No other additives are needed if using one of these products.
Can't go wrong with WIX oil filters.
CD's specializes in older boat and performance engines, and they recommend this oil for my 350Qs.