Right now I have unlimited licensing for '04 silverado's and sierras. Just installed a 6L and am considering applying RTT to the OS. I'm confused though, on the pricing page it looks like it costs 2 credits to apply the RTT. Bit in another thread: http://www.hptuners.com/forum/showth...ht=rtt+credits Chris states that it's only 1 credit. I'm confoozled. For 1 credit I'll try it, for 2 credits though I'll do it the old school way Can someone clarify for me?