If it looks like a duck and it walks like a duck it ain't an aardvark. Maybe after 3 tries you will get the message and go back to the stock heads since the Snyder head is as good as it gets for now.
I just measured my Snyder's 5.5 head and an original stock head and they both measured exactly the same at 2.2275". The Snyder's head looks excellent in every way. It's still in the box it came in, but I don't foresee any problems and will use all original studs and nuts.
If it had been too high, then I would have milled the bosses down to the correct height.
I only had two uncut 5½ heads in stock and mine measured 2.249?, and 2.250? with my cheapo Chinese micrometers. The ? means that it is inbetween the marks but is not numbered. If you need that decimal, make up one and fill in the blank as it is close enough for my needs. I have no idea when these were manufactured and I do not see a date code stamped on the boxes however I do suspect these came in at different times but it is anyone's guess whether they were machined in the same batch.
While I do feel badly for the original poster's circumstance, I cannot help but think that this entire thread has done very little positive for the situation as a whole, ...and in reality as probably created more ill feelings amongst those who have posted than anything. While everyone is entitled to their opinions too, for me personally I am of the opinion that a parts manufacturer should not read about a perceived issue from a public forum unless they have shown gross negligence first. Just knowing Don Snyder and his customer service, I feel comfortable in saying he would have done whatever it took to make the customer happy, --even if it required refunding all of his customer's money.
The other thing I am truly having difficulty understanding in all of this is all of our perceived expectations. We all know when we purchase this aftermarket head that its design has been deviated from what the original head was. It really is not touted as 'manufactured to original dimensions and specifications', ...but instead it is simply offered as "original in appearance." Is there a difference in this instance? I think so.