By the way this is what he had to say about the truck to me via email;
Hi Jason;
I bought the Blazer 5 yrs ago from the son of the original owner. He had a ranch south of Calgary and was getting snowed in in the winter. He only drove it for three years then left it parked in his garage (he was pretty old). It had only 17,000 miles on it at the time.
It now has 32,5xx miles on it, apx 3000 miles per year. Oil changed 2x/yr. I had the engine made more efficient by Davenport motor sports (re-curve distributor etc) and it now gets 18 mi/gal and has much power. The price is $7000 firm.
There is a small spot of rust about the size of a quarter behind one of the wheels and another on the front of the hood about the size of a paper clip. a few small traces here & there on surface only. I don't think there is any on the tailgate or frame (dark outside now).
I think the cracked frame at steering box only happens to trucks that have been put under excessive stress (4x4ing & big tires). This truck has never been worked like that. It is not a full convertable top, I think 74 or 75 were the last years for that.
trany is 350 & t-case is np-203. I have assumed that the diffs are 373, it is at 2500 rpm @ 100 kmph.