Only 1of the 3 A-D pickups I have owned had a working speedometer or odometer. And it was a 50 3/4 ton with a V8 swap. So who knows? My last Chevy was also a 50 3/4 ton with probably the original 216 and 67000 +/- on the clock. But it sat for 27? years before I got it and needed lots of work to get back on the road. I drove it and had fun with it for 5+ years and never had the head off of it. So this doesn't really answer your question. Sorry. ☺
