Lawn Boy 8155 Transmission grease and clutch

I'm in the process of cleaning the old 1986 grease out of my barn find Lawn Boy 8155 transmission. I've read in some treads that it requires 3 oz. of new grease and others say 6 oz. I put a little over 2 oz. in it and it seems almost full. Anyone know what the correct level should be and the best grease to use? Also, I could not remove the clutch plates from the axle because of rust on the axle. I did not grease the clutch plates but only cleaned them. Should the clutch plates be greased? Any help would be appreciated.