Wow. Stock they are in the 14's, although the 94+ are heavier than the Fox bodies. I am assuming by I/H/E you are referring to intake, heads, exhaust, although the usually "upgrading" of a 5.0 involves a cam...but if they go through all of that and are not below 14's, they fail as a driver. My 2-ton car with the stock 5.0L with a grand into H/C/I is in the 13's, and a Fox-body with the same engine and a solid foundation would be in the 12's.
To be fair, the same amount I put into the 5.0 could be put into the GTP and come out just as fast or faster, but I feel calling the 5.0 junk is a little absurd.