hey man, sounds like the gift that keeps on giving...did you try rotating the driveshaft 180
degrees on the flange of the rear diff, could have taken it somewhere and had gotten it balanced.
congrats on the no oil leaks and first oil change. I just 150miles on my build, no problems so far. bout to do a grand canyon trip in a week or so. can't wait to boost, granny shifting everywhere is harder then it seems.
get some vinyl do it yourself, I didn't even notice the chrome until you mentioned it. I'm sure it sticks out more on black than red.
good shite though, what numbers are you expecting to see on E85 and a tune?