I'm looking to get an '81 era 1-ton 4x4 Crew Cab. It has what looks to be a factory 6-cylinder in it (4.8 liter 292ci). It also has a TH400/205, and no tag on the 60 front indicating gear ratios. The story is that it used to be a truck owned and used on the Alaskan Pipeline. What was the last year GM made a 292? And would a 292 in a Crew Cab this size be any different than any other 292? I'd also assume with a 6-cylinder that the truck would have come with 4.56 gears. Would you bet on 4.56s or 4.10s?