From the perspective of a guy who grew up around flathead Ford V-8's and 216 Chevvies, the 2nd.-generation Chevy sixes are more reliable, and produce more power than anything but some of the highly-modified 1st.-generation sixes. The 194 and 230 Chevy I-6's had chronic block-cracking problems along the valve lifter bores, which turned the block into a boat anchor. The 250's didn't seem to have as much of a problem with that, and the 292's are as rugged as a bank vault.
I've built several modified 250's that would give a V-8 a run for its money, and they still got pretty good gas mileage. For stump-pulling torque, pick a 292, but be prepared for the truck to swerve toward every gas station you pass. They really like their fuel! Add a 5-speed overdrive transmission behind a 250, or a 4L60 automatic with OD, and use a 3.73:1 rear end, and you'll have a good all-around daily driver that will keep up with traffic and still get some pretty decent fuel economy numbers.
Jerry
