I've got an old 72 Chevy 4x4 with a TH350. I'd like to change out the trans fluid and filter. I'm about 99% certain I can go to Wal-mart and buy the cheapest Dexron they make and I'll be fine, but I thought I'd check here first. Am I missing anything? The truck doesn't see particularly tough duty, a light trip to the dump every now and again and plowing a 200 yard driveway in the winter.