ok guys after I put on the new wheels(18x9.5), tires(295/45/18), 2" rear loweing shackle and hotchkis swaybars I've noticed 2 things.
1. It pulls slightly to the left at highway speeds, sometimes more than others.
2. There are times at slow speed braking where it the truck starts to pull left or right. Doesn't favor one. When I apply the brake harder the wheels may go in the direction they were pointing. ie if I was veering left and ally the brakes harder than usual the wheels will start to turn themselves that direction.

I've checked tire pressure and all is good. I'm going to try and put the stock wheels back to too see if that makes it go away, but other than that I don't have any idea what would cause this. Couldn't be the swaybars could it? I have rechecked all the torques on all the linkages too. Only think I can think of is that the new swaybars have slightly fixed the chevy lean and are knocking some things out of whack. I can't see alignment changing after any of this though.

 

Changing the size of the wheels and tires can have an effect on the alignment geometry, believe it or not. Since you seem to be having pulls to either side though, it may just be that you're experiencing the effects of road crown (the curvature in the road for drainage). Are you in the left lane when it's pulling to the left on the highway? Try the right lane and see what happens. Either way, it's not a bad idea to have an alignment done, especially if you just dumped a bunch of cash on new tires...it'll help to increase tire life by minimizing abnormal wear.

 

Agreed Bud. Plus I noticed the same when I did my shackles and 17" denali wheels.

Also, what sort of tires are you using? Some of the high performance speed rated tires just tend to pull more than others. Its just something you get used to, especially if they are a directional tire.

 

This is a hankook ventus RH06 directional 295-45-18

 

Wider tires tend to follow the road more than narrow tires. Just one of those things. Do like bud suggested and pay attention to the surface of the road when it pulls. I am willing to bet the road is either slanted for drainage or there are wear groves in the road from heavy traffic.

 

Looked at that today when I was out at lunch and pretty sure that you and bud are right.

Thanks guys,
Andrew