do it yourself, it will save you a decent amount of money and it will not be that difficult on a truck. i just recently put power steering in a 69 roadrunner, i had to get the steering box from a salvage yard and got it redone by redhead steering which is one of the best steering companies in the u.s.
http://www.redheadsteeringgears.com/ i got the pump/pulleys/and brackets through a catalog. and overall i saved a couple hundred bucks from doing it myself and a shop will charge you alot more for parts and the labor fees.
