Scotty,
I inherited my father's 1994 2 door 4X4 Chevy Siverado Blazer with 145,000 miles. It still runs well and looks great since its been kept in a garage. I was wondering if it will be a collectors car someday and I should hold on to it or I sell it before it loses anymore value?
That was a mainstream car, so unfortunately it will never be a quote on quote collectors item. However, it probably has sentimental value to you and GM was making better cars back then then they are now so you may as well just keep it. Don't look a gift horse in the mouth.
I would sell it
I think the first Gen K5 (1969-1972) could become collectibles esp. if very low mileage and well kept (which most of them are not) similar to the older Broncos. But beyond those years, probably not.
No collectible value in those, or any other modern day car. You could probably sell it and make out alright. They were pretty reliable for GM stuff.