Bought used in mid 1986, the 1982 GMC K1500 Sierra Classic shown above was my first GM diesel-powered pickup. The push to buy this truck came from my ownership of a 1973 K5 Chevy Blazer I'd owned a few years earlier. That SUV was extremely useful, but it was not a pickup and its fuel economy really-really sucked. I wanted/needed a full-size pickup truck that delivered acceptable fuel economy, given the post Mid-East oil embargo world we lived in. Being a GM guy, I knew it had to be either a Chevy or GMC. No one I knew owned a 6.2L diesel at the time and I knew very little about the engine beyond what the GM brochures contained. I took a chance.

This GMC diesel had just 51,000 miles on the odometer when I bought it, but the truck had seen some tough use by what I suspected was either a rancher or horse owner (the hay and gooseneck hitch gave it away). The original factory-installed TH700R4 4-speed automatic transmission had been replaced sometime prior with the simpler TH350 3-speed automatic.

The introduction of the 4-speed TH700R4 for the 1982 model year was just short of disastrous. Those early 700s failed in droves, and aftermarket companies sprang up to provide conversion kits that made it possible to install the more reliable TH350. The non-overdrive automatic worked well with the 55-mph national speed limit at the time, but not having an overdrive made it not well suited for the higher freeway speeds that arrived in 1995 with the ending of the 55-mph national speed limit. I knew I had to re-install a custom-built TH700R4. Of all of the modifications and upgrades I added to that first 6.2L diesel pickup, the 4-speed overdrive automatic provided the most bang for the buck both in terms of fuel economy and making the truck more pleasant to drive. Following the installation of the 700R4, engine and drivetrain noise disappeared while at highway speeds, and fuel economy jumped by a solid 5-mpg.

In retrospect, most people consider the '80s 6.2L diesel powered trucks were a step in the right direction for GM. While not perfect, the 6.2L diesel fulfilled its role as a fuel economy substitute to the gas engines of the time, and the trucks performed their expected role with style and solid value. It's now 2013, and based on the current level of correspondence and activity in the bulletin board, it appears there is still a significant interest in this generation of both diesel engines and the trucks they came in. Coverage for the '80s trucks and the 6.2L diesel engines will continue to be a part of what we do here - far into the future. Thanks for reading.   TDP

Since 1996, TheDieselPage.com has been providing the most valuable information on the net about the 6.2L Diesel - how to save money on maintenance, make it last and to improve performance. Aside from being the very first web site that focused on the GM Diesel, our own 6.2L Diesel ownership roots go back to 1986. We love the 6.2L Diesel. Whether you just bought a 6.2L Diesel or you've owned the same truck for 20 years, our time-tested and proven information is now available in a series of books that 6.2L Diesel owners overwhelmingly applaud. Please visit our Books page to learn more.