One thing everyone discovers about a lift and big tires is the effect it has on fuel mileage. Now, K5s aren't exactly the most aerodynamic design ever created, and in stock form I got 13-14MPG. With the lift and 37's I was getting consistent 11MPG tanks
From 1982-on, K5's were available with 6.2L diesels. They aren't powerhouses, but they are known for getting great fuel mileage. I had been on the lookout for one when a stroke of luck hit. My roommate at the time found a 1991 1 ton 4WD Chevy truck that was being sold by a county flood control department. He wanted the truck for the Dana 60 front axle, but I was interested because it had a 6.2L diesel engine! The best part was the fact that, being a flood control vehicle in AZ, it never had many miles put on it; the truck only had 50,000 original miles! We made a trade: the 6.2L diesel for my TBI 350. Within a couple days the truck was minus a front axle and this:
I had to pull the intake and do some cleanup. Mice had made a home in the valley, chewing through the supply hose to the injector pump and leaving all kinds of biohazard behind:
I got it all cleaned up, put back together, bumped the timing up a bit, and swapped it into my truck. Small block to 6.2 swaps are super easy since the engine drops right in using the same motor mounts and the trans bolts right up. I also swapped in the bigger diesel radiator and shroud, hydroboost, second battery tray, diesel instrument cluster, a Racor 10 micron filter assembly, and a few other odds and ends. Here's the result:
Not long after the swap it went on it's first off-road adventure as a diesel-powered K5. I went on a run to Crown King with members of the Hummer gang (yes, they actuallly wheel their H3's and H2's!). We even had some Jeep guys along for the ride, as well as an 80's Ramcharger:
The 6.2 ran great. This particular engine was the last year that the 6.2 was offered, and at 165HP it was the highest horsepower J code 6.2 made. 165HP may not sound like much, but thanks to the extra helping of torque vs the 350 it was pretty spry.
This run was done at the beginning of March 2009, and up near Crown King the elevation was high enough that there were still patches of snow on the ground:
Around the time we hit the first traces of snow I snapped a couple pics of my gauges. The temp ran lower than the gas 350:
The best gauge pic is this blurry pic of the fuel gauge. Note that this is with about 90 miles on the tank, and 30 or so at low speed off road:
Gotta love the efficiency of a diesel engine!
We finally roll into the thriving metropolis of Crown King and stop in the local watering hole for a hot burger and a frosty beer:
Well, that's it for now. Stay tuned for our next episode of "How Max ends up with a 12V Cummins in a K5 Blazer".