[venturaII]

I'm going to break ranks and say change the oil if you have the chance. Not out of need, per se, but more out of opportunity. While the oil is very likely fine at this point, you still aren't exactly getting ripped off with a 5K oil change interval of an unknown fill. If I was about to take a 600+ mile trip of constant rpm and engine temp, I'd prefer a nice fresh additive package in there, doing it's best to keep a motor clean and shiny on the inside. If you have 5K miles of typical stop and go daily driving, it certainly wouldn't be a BAD thing to change it before you leave, if you had the chance..