Thanks Denny. My plans are to give the truck to my 13 y.o. daughter when she gets her drivers license so yeah, I plan on it lasting another 60 years. It was originally a California truck but is now a Colorado truck that will be a daily driver and we use mag chloride here - if you ask me, too much now that people have forgotten how to slow down when driving in inclement weather.
Keeping the drains open does seem like the most logical thing to do.
Thanks