Yea, to be really on the safe side, just drain the oil and refill, put in 3.5 quarts, and check it. The filter usually holds about a .3 to .4 of a quart. Put in 3.5 and check it cold. If you're at the top, start it and wait and recheck. I will say that when I do the changes, I usually have oil left over in those 5qt containers you get when you buy oil. That means, for sure, this thing uses less than 5.Thanks again for all the help. Will probably drain it out tomorrow and do a clean oil change and just put in 4qrts and go from there.
It's weird the habits you develop working in a shop. We changed oil frequently on all kinds of models and if there was a sticker on the hood we used it as a guide, but if not we just did the method I posted, started low, checked it to make sure it was between the top and bottom marks (which usually correspond to 1qt total) and went from there. We never looked up capacities. It would take too long and those jobs only pay like .4 of an hour. The bottom line is it needs to be filled and at the top dot when at operating temperature. Focus on that more than what number is on a sticker.
I never blew up an engine doing that method in a decade of service. I DID however blow up an engine when I was still in automotive college, working on a Sunday and trying to do 3 cars at once. A warranty job got an oil change added to it mid-job, I drained it and forgot to fill it. Let's just say I had a very fun time tearing that engine down to the crankshaft and rebuilding it for free. The upside was, after that, I had all these old timers asking me about the new engine because I was the only one in the shop to date that had rebuilt one. Trial by fire=)