There is one issue on these 3.8 engines that isn't an issue until it is...
(And I bring it up because you are using the car as daily driver, and such a long distance...)
That is the timing setup. These cars used a nylon tip gear with a metal chain. Age and time the nylon wears and gets brittle. Sometimes the teeth wear down, just as often they break off one or two at a time until not many hold the chain. It will run fine with no signs or issues until it simply skips and jumps time. Will run and drive fine to where you park it, then on restart it'll be shooting gas up in the air out of the carb. Wont hold a timing reset either.
The fix is to buy a metal timing gear and chain set, same as the
grand national motors works good. Not a gear drive, just metal gears and chain. $100 gets a good high quality unit, and if desired, change the oil pump and check the front cover for wear while you've got everything apart.
I put that under the preventative maintenance section of these cars, and I've kept those little 3.8s going 170k, 270k easily on a regular basis. They're great highly dependable engines if taken care of, albeit low horsepower.