I installed my Nelson Pcm today on my 03' Silverado 4.8 ECSB and I cant beleive I waited this long and actually bought a Hypertech before this! Didnt have any problems installing cranked like it came off the lot . The only thing I need to know how to do is reset my GM oil Monitoring any info would help! It really doesnt shift hard at all but it shift very quick which is a good thing and in second it gets up and is a beast. I've onyl put 5 miles on it! LOL! So I know I havent felt the best of it I hope. I got the 93 octane tune and told Allen to give me all performance and gas wasnt a factor. Ill be getting a Transgo.servo,pinless acc and cooler in the coming weaks so that along with Allen should be able to firm up my shifts! How did some of your relearn periods work how many miles untill it reached its peak! I had no pinging( I ddint hear any) and like everyone else has said Allen was more than a pleasure to deal with we have exchanged many many emails and I'm gonna get him to do a turbo setup in the months coming! Thanks Allen! Ill post some before and after dyno #'s in a week or so once I get some miles on it! Any info I need is appreciated