Just wondering if anyone has had any experience with driving a 671 Detroit? One of our farm trucks has this engine with a 7 speed Spicer transmission. Its a 86' GMC Brigadier with a dump bed. I hate driving the truck compared to our other trucks. It doesn't seem to have much power, even with a load that isn't that heavy. Once you start lugging on a hill, you can downshift, but its still lugging...downshift again and it could still be lugging. It loads easily and shifting gears is worse...even worse than a regular semi truck and we all sometimes think a semi truck seems to have a mind of its own with shifting gears. This one is very picky about the gears and the rpm's used and when it grinds, its loud. I've drove several semi's on the farm, most being a 379 Peterbilt with a Cat engine that shifts nicely. Anyways, just wanted to see what everyone's experience was with driving a 671 Detroit, and I'm curious if there is something wrong with ours or if this is just normal for these motors because sometimes I think the governor is messed up. Anyone here drove a 671?