Drain holes in a Blazer Floor?

[phlegm]

Hi guys, as told on another post. I have a line on a 72 blazer thats currently off frame and being stored in a shop. I am working on budgets and selling it to the boss. I have always said if I did one of these I would spray thick bedliner on the floor and put drain holes in the low spots so if I am topless and get caught in a down pour i am not bailing out the truck. Is this a normal thing? I searched the site with some keywords but didnt see an obvious thread, plenty on bed liner being thick but not so much on drain holes.