Vintage Chinook - advice?

Is it a van( Chinook did make B vans) or fiberglass Class B+(C)?.The engine is way,way before Powerstroke and as I recall,kind of a dog but fairly reliable.Here is an answer to the engine question from an old forum found through Google search "1987 was still mostly the 6.9, though some IDI gurus claim a few 7.3s were slipped in late in the production run. As far as being a good engine...well yes most definitely as long as it has been well maintained, and by that I mean mostly oil changed every 3-5K miles or more often and not overheated or run out of oil.....6.9s tend to "use" some oil either from blowby or leaks or a combination of the 2. Don't figure on pulling teh speed limit on a steep grade with a heavy load, even with the 4.10s and automatic......it will lose some speed. Add a turbo and it will be better....head gaskets may be a worry, every year was better and better, but the '87s still needed new head gaskets pretty often. My '86 made it to 152,700 miles before I had to change teh gaskets. Injectors and injector pump life are a function of fuel system maintenance good clean fuel with lots of additive and some say not running out of fuel will go a long way to improving the life of teh pump and injectors. Some have had to change pumps at 80K miles or sooner, others still calim all original at 300K miles and beyond, but usually it's in the 100-150K range as far as mileage for replacing them. It is also worth looking at the gear ratio and transmission you have to dtermine towing ability and what your max speed will be. For example C6 and 4.10s will acclerate almost right with a gasser but will leave you with fuel economy only slightly improved over a gas truck(still significant though) and high rpms on the highways such that the engine will redlinde between 78-82mph yet you will be able to tow anything all day at 55mph. On the other hand 3.07s and a ZF-5 manual will leave you in the low 20s as far as MPG and you can bury the speedo and then some. Yet your towing ability will suck especially in the hills and mountains and your accelerationmay leave something to be desired. 3.55s and a manual are teh best compromise IMO...Upper 10s fuel mileage wise empty and can still tow moderate loads at highways speeds,
J.D. "