i have an idea on why this is happening but have a feeling i don't really wanna know lol. what can cause this, it looks like the driver side is worse than the passenger side.

First thing that comes to mind is toe, but that would mean something you don't want to know.

Is it like feathing ??? is on both inside slicks ? some of this has to do with rim offset.

I have seen slicks wear more on one side because of turning the same direction all the time. like on to the track or the return road.

"I have seen slicks wear more on one side because of turning the same direction all the time. like on to the track or the return road"

One of the reasons to rotate them regularly if you want even wear!
Mike

yeah i rotate them once or twice a year, and is a 14 in rim w/ 4in back spacing i think.

Your axle housing is flexing. I would inspect closely for cracks. The DS wears more unevenly because it is loaded harder.

i had new slicks at the start of the season & i noticed feathering on the inside of the slick. got worse after a couple of meetings. found the tubes on one side were becoming egg shaped & my diff was flexing. fixxed the diff, swapped sides for the slicks & reinstalled. 2 meetings later the feathering marks were gone & everything looks even across both slicks. i think you may need to remove you diff for some measuring for squareness. your slicks are trying to tell you something, you need to listen.

That thing has a dana right? Also if I recall when you first put that back on the track didn't you have a issue with bracking tail shaft housings or something? I recall you saying that the rear end was pointing at the moon??? How does the thing roll? Does it push like a stone? If that thing has a dana, even with leaving off the botton, I really do not think the housing is flexing. I think you have some issues with things not being "true" I would check from the center of the front wheels to the center the rear wheels. I think there is some issues there???

It's got an 8 3/4 in it. And Brian, once or twice a year aint enough rotating. 30 runs max.

You can check the housing to see if it is bent with two long straight edge, longer is better, and measure off of the axle flange (not the brake drum or rotors, check the width on the front of the axle flange as far out as posible and then the rear side, same thing straight up and straight down. If it varys more than a 1/16 of a inch you may have a bent housing Let us know waht you find, BTW I have seen, mine included, housing that where in the car cockeyed do to misaligning the adjustmenst on the ladder bars or four link bars 1/8 inch misalignment raises heck with the tire contact patterns Makes it hard to go straight also

Hmmm... I dont think I've ever seen my rear tires wear perfectly even. But I very rarely rotate slicks maybe once or twice a year. The sidewalls are usually shot before the actual tread ever wears out. Or the compound starts to lose its stickyness. I saw your car on the lift down at SlipTech when I dropped off my Dana for some new gears. I really wouldnt worry about it to much. Maybe I'll see you Sunday at NTR!