SCUMBAG ALERT! TURBOVAN Phoenix.
A bit of a **** show to be sure, but I for one can see both sides. I will say that if I bought a set of rocker arms as a "set" and they were different ratios I think I would be a bit pissed off. It seems to me that both sides of this feels wronged and thus have dug in, however Turbovan appears willing to wipe the slate clean and undue the deal completely which is probably the best course of action here.
I have bought plenty of used parts over the years as I am sure all of you have, not much worse than buying something only to find out it isn't what you thought it was, especially if you are buying it when you need it. Likewise, as a seller of used stuff, many buyers seem to think they are getting brand new pristine parts for 1/3rd of the price and then complain. I have lots of parts, don't sell anything because I do not want to deal with jackasses, likewise I seldom buy used parts because I don't like getting screwed; sure there are deals out there but way too many people advertising things that are not what they say they are. I'd rather pay retail for new stuff than deal with people.