I was curious if any of you have ever run into this.
Last year I was looking at a few photos of my 5500 pound truck and noticed the passenger side rear lifting up off of the ground during the start of a pull. Weird right. Well I had also seen a few guys moving some weight to the rear or their trucks so after seeing the pic I thought I would try it. I moved a 75 pound weight out board of the frame right behind the tire. In comparison to the other trucks and past footage I picked up ten feet. I was just wandering if any of you had ever seen this before.

What you have described is know as unloading the rear end.
There are sleds out there that don't put enough pull down on your truck as you leave the line. usually it's a long cable hook sled . and we too shift weights around on a few sleds here. but most of your self propelled sleds let you know their there from the get go.
Dan

When ever I'm at a pull with a sled with a long cable I usually put 600# in the bed and 400# up front.

We have several self propelled sleds around here that are very light on takeoff, hardly know they are there, until they "hit" you at the other end.

Yeah it's because the sled isn't putting enought weight on the back of the truck. But the reason the right side lifts is the same not matter what. The axle twists and picks up the right side. Ever do a single track rear end burnout? The right side always spins, because the housing puts pressure on the drivers side, lifting the right side. The thing is this always occurs. So if you have the option you might build a little bit of preload into your rearend. Learned that from a drag racer!