Thanks I'll give that a try Alloro, I always value your input. Over the summer the fuel pump I assume was making a mid pitch humming sound extremely loud, but only did it for 1 day, and it never occurred again, but that was deff coming from the fuel tank area. Albeit recently I've been hearing a high pitch version of the same sound but from the front of the truck, I think only cause the 2 times it's done it was when it was below 30 degrees and very windy upwards of 40mph gusts here recently in NJ. And only right after I start the truck. But that was about a week ago. It may have been near the fuel tank, if it happens again, I'll hunt it down.

On a side note, last night when I went up the same hill it does it all the time, it did NOT do it last night, and I did notice I was tacked at 3100RPM's and the truck didn't shift till I leveled out. I rarely hit that high an RPM for long. I usually hit the hill at 50, but this time I hit the hill at about 40 cause I had a PA driver in front of me that didn't know what the right pedal was for, or what a speed limit was. So I stepped on it to finally pass them, and that's when I noticed I was at 50 with those RPM's and I had only dropped to 49mph from 51 and that was keeping the pedal at the same position. RPM's stayed the same. I had just over a 1/4 tank.

Oh forgot to mention in the 1st post my truck has the 4.6L Vin 6.