Oil capacity 1976-80 5.7 L - additional marks on dipsticks

Hello, Just picked up a 1976 SeaRay 300 SRV Weekender with twin 5.7L Crusaders with approx 750 hrs. Port engine appears to be original and starboard a bit newer, but I can't find serial numbers on either engine. Was changing the oil and noticed that both dipsticks had additional Add/Fill lines crudely etched in (with a dremel tool probably) that are considerably higher up on the dipstick. 6 Qts brings the level to Full on the factory markings, so would take another quart at least to get the level up to these mysterious additional marks. Would appreciate any input regarding the oil capacity on these vintage engines! Thx

Those extra marks could be while engines are running and warmed up, Wild guess! contact previous owner if possible

Of the scenarios I can think envision, none really matters - what does is 1) making sure the proper quantity of oil is in the crankcase & 2) that the dipstick accurately reflects FULL and 1 qt low. I'd check with the factory to verify but would expect 6 qts to be capacity....if that gets you to FULL, then use the original dipstick marks on ignore the Dremel'ed lines...

makomark said:

Of the scenarios I can think envision, none really matters - what does is 1) making sure the proper quantity of oil is in the crankcase & 2) that the dipstick accurately reflects FULL and 1 qt low. I'd check with the factory to verify but would expect 6 qts to be capacity....if that gets you to FULL, then use the original dipstick marks on ignore the Dremel'ed lines...

Click to expand...

Thanks guys for the input. Forgot to mention when I pulled the old oil out of the engines, there was definitely more than 12 qts of oil, probably closer to 14 qts. My worst fear is previous owners have been running these things overfilled for years. Were they trying to take into account the angle of the engines? Geez, who knows

The installation angle range is accounted for on the factory tube sticks.....who knows...