The M1008? It can drive 55. Sing it. If you daily it, you'll be fixing it. It's a bit unreliable because of the bean counters at GM, but it's mostly unreliable because it's 40 years old. If it's rubber, it's rotten. Most of them have been sitting for a long time. You'll have fueling issues almost immediately and will replace everything but the injection pump because you don't want to pay to fix it. The problem will be the injection pump. Just deal with it when it happens. Yeah, they're expensive. They'll be more expensive later. You can take that to the bank. Just fix it ASAP. You can spend a lot of money putting a turbo on it and breaking it. Maybe it would be fine. People are safely running like 3 PSI, so I reckon why bother. Put some turbo mufflers on it. They're lighter and only louder than stock when you floor it. You will feel the difference. Stack two intake filters in it and put extended all-thread in the intake manifold with new butterfly nuts. Immediately able to return it to stock, but there's room under the hood and you can decide if you're into the noise to power ratio, because an open intake on a 6.2LD sounds like a mutant Quadrajet. Also, an open intake on a 6.2LD lets the tuna can puke exhaust into your windows when you roll them down. I solved that with a draft tube, which had a low spot that was its own problem. I have a venturi to weld into the exhaust for this, but it's not installed yet.
If you want a reliable work truck you don't have to think about, get a Tacoma or a Tundra. If you want to tinker for the rest of your life, get the M1008.
