Those 70's model pickups are sure tough. If the P/U hasn't been beat it should be in the area of $3-4,000. Tough to tell without seeing it. The 400 engine is a good motor. From my limited experience I have learned that you are not able to bore them out very much due to the thinner cylinder walls. The 400 is basicly a larger bore 350, using the same block. Fuel mileage was not very good on those trucks in those years. But, if it is a factory bore or maybe .30 over it should be just fine. They did run strong!! The 4 speed trannys in those years were quite bullet proof. Granny gear is a very low ratio and works well on trail driving or hard pulling.
One good thing about a 1977 model year is that it shouldn't have any smog control, unless it was a "California truck" which there are a few around. If my memory serves me correctly late 78 and 79 started the emissions equipment being installed. The quickest way to tell is looking at the gas filler neck. In 77 it should be a large filler neck hole which was compatible with the old style "regular gas" pump nozzle.
Anyway, I will shut up now. Good luck with your 77. They are quite tough.
Brian
Show Low, Arizona
