Actually the HD leveling kit uses a progressive rate spring(not VR) and in my opinion the rate is way too stiff.

 

here's a + for Thuren's customer service- what a great guy! I'll let you know how it runs when I get the lift installed, but he got back to me right away. I'm out of the country, using email and only 2 core dealers got to me after I emailed them- one 4 days after I inquired, the other took a full week to get back to me.

Don answered all my questions promptly.

 

So, have you used the KORE HD leveling kit in the past and then switched to Thuren? Also, I noticed in your sig that you have mini packs in the rear. Does your truck sit level?

 

No, I never run the KORE kit. But, through research and after reading several testimonies I have come to this conclusion.

Yes, I do have the mini pack in the rear, and the truck will sit level. There are 1/2" spacers in the pack that can be used to fine tune the ride height. I have mine set about 1 spacer on the high side to accommodate towing and hauling loads.