hey guys I am getting an 84 gmc with a 6.2 liter diesel. I have heard the lack power but are upgradeable. I would like any information on this issue. thanks fellas
Ive never looked into it but you can use 6.5 turbo parts on a 6.2 for a little more pep, do a search on it and you should find some info on it.
6.2s are about as powerful as a stock 70s/80s 350. Unlike a Cummins or a newer diesel they were designed for fuel economy, not power. First thing I would look at is gearing. My truck is quick enough for my needs and still gets 17-19 mpg highway with N/A 6.2, th400, 3.73s, and 265/75R16 (~32") tire. A lot of 6.2s came with 3.08s, great for fuel mileage, terrible for acceleration, and part of why 6.2s have such a bad rep. There are 2 popular options for a turbo: the 6.5 turbo or a Banks turbo kit. The 6.5 is cheaper but has 2 drawbacks. If your truck has a/c the turbo won't fit with the a/c box on the firewall. There's also a clearance issue with the passenger side exhaust manifold, I've heard of people grinding a little off the frame rail to get it to fit. Other cheap mods include: J-code intake (3/4, 1 ton, and military 6.2s had these stock) turning up the injector pump (advancing the timing)
