http://www.forabodiesonly.com/mopar/showthread.php?t=193577
I didnt go the proper route when I did this setup. I went with a single spring froms Hughes (spring #1110) with matching retainers and locks vs the double spring that Lunati recommended. The single spring /w damper was approved by Lunati when I called them...tho they will age quicker i assume. I had new bronze valve guides installed and had mild porting on my heads as well. I might have had a little luck because my retainer-to-guide clearence would have allowed me to go up past a .600" lift. Typically anything above .500" lift you need to make sure you have proper clearence. Thing runs great and pulls right up to 6,000 rpm no problem. Any questions let me know.