What kind of oil do you run in your older cigs? I have 1988 420 HP engines and I run Valvoline Racing 50 weight with a quart of Lucas oil stabilizer. I use Wix filters!
What do you run?

This is just from my own experience. I've found that if you are running thermostats,(oil and water) 40 wt oil is fine for your application. I feel that 50 wt is too thick and causes extreme distributor gear ware.

I do not run a water thermostat, therefore I feel that 40 wt is just too thick to be pumping through the motors, especially when cold. I've had good luck with Pennzoil 20/50 and change it every 10 hrs (blower motors) Fram HP-4 filters.

Kurt

I tell ya, Mercury has good oil and we use Valvoline 20w50 racing oil in some of the engines I have built. When we tear them done to do fresh ups or for more power, all the gear inside looks great. Piston skirt wear is very minimal.

Pwrbt33- John S.
Offshore Performance
410-827-0200

Always use Mobil 20w50 in my natural engines and Mobil 1 synthetic in the Blower motors. Both products work fine with or without stats. I would save the $ in your application and run the regular Mobil.

Baldwin racing filters No. B279