Pinging?!?!
 

I don't get into WOT very much, but the other day i had to accelerate fast, and i started hearing rattling coming from under the hood. at first i thought that it was just gravel stuck in the tires, but than it happened again this morning. Is this pinging? also i was going to do the Sixliter Tune next week, but i guess i cant do that now :unsure:. I have a 1996 5.0 with true duals and a CAI. i don't have any cats in it right now, but i have to put some in before next inspection. gonna check if i have o2's. ~ Thanks!

never mind, I think its the fan hitting the shroud.

if the fan is hitting the shroud when you accelerate the first thing I'd look at is the motor mounts. I'll bet money they're dried, cracked, and allowing the engine to lift.

In order to test the mounts without possibly destroying the fan & shroud, pull the belt off. Then start it up, put it in reverse and hold the brakes while giving it gas, see if one side of the engine starts to lift. Then do the same with it in 1st and see if the engine lifts.