Just read the posts on this forum and you will get to know the ones who know their stuff, then just listen to the adverage of what we tell you, and you should be pretty safe. Always beware of a radical statement untill you get enough information to verify the statement. No mater who makes it. Any of us may have a brain infarction at one time or another, and give out bogus statements.
I put a TST #6 plate in mine, and I could not be more satisified with the performance, except one thing, that being that my lockup converter could hold the additional torque when the throttle is snapped open at about 1750 RPM. Have to lean into it, not jump on it. My fuel millage is close to the same, but the torque is unbelivable when compared to the stock plate. A friend just bought a 96 ctd identical to my 94. When he brought it by for me check out before he bought it, I had him drive mine so he could get an idea of the potential of the truck he was buying. He and his son were blown away.
In short, the plate and straight exhaust and a set of gauges (my next project) are your most economical and safe power upgrades.