Ford Repair: e150 tune up, gas millage, van conversion

Question
hi, I have a 1984 econoline E150 getaway van conversion with a 302 in it....150,000 kil. the bolt that holds the inside engine cover on was rusted to the point it had to be sheared to see the engine, which tells me its been years since a tuneup. it runs well, sounds strong, but only gets 14 mile to the gallon...do you think it should get better with a tuneup, and what do I need to get? I already had a new radiator, it has aircon, but it does not work, and I dont want it to. have checked the air cleaner, and it is not that bad.

Answer
I don't think you get much better gas millage by changing the plugs however.  I would recommend changing the plugs for the health of the engine as well it does help it runs cooler.  As for the bolts, it the age of a there quite a bit of heat in that area and it does oxidize the bolts.