I asked the same thing about putting a Western v plow on a K-5 blazer. After some thought I realized even though you could physically do it with some sort of stiffer spring to hold it up doesnt mean it's a good idea. Your truck will not like it. The best point that was given to me was the fact that with a v plow you will be pushing snow in scoop position rather than "plowing" it off to the side. Your transmission will not like this. I must point out though that I have not plowed with a v on a 1/2 ton or on anything for that matter. so this is just my opinion. Maybe someone will have something to say that has some experience with them.
Neal,your K-blazers solid front axle is stronger than the F150's IFS,so i wouldnt worry so mach about your older truck,but a new one i would being its under warranty and I wouldnt want to jeapordize the warranty just to have a V-plow.
I wouldn't put a v-plow on anything that didn't have 8-hole rims. I bought a 2500 chev. planning to put a Boss v-plow on it. I had bought the plow already and I brought it in to the dealer to install it. Found out I only had a light duty 3/4 truck(5 hole rims) and they would not install and highly recommended me not installing it myself. Luckily I bought the plow and truck from that dealer and they gave me my money back for the plow. I was still unhappy that they sold me the truck knowing that I wanted to put a V-plow on it. As for looking into a poly V-plow, that won't help you out for weight. They weigh more then the steel ones.
I talked to my Boss guy the other day and found out they make a 7'6"mount for a Ford 150 so I am thinking about buying the mount and putting a 8'2" boss on a new 150 four door.So far my half ton blazers have done great with the Boss'.The older one has aux springs in the front and it handle the 8'2" better than some of my 3/4 ton.The blade has been on the truck around three years.