Is my 904 toast?

Could have been a loss of traction. Go out on the street and do it again and see what happens. If it's a transmission problem, it's already broken. Not like you're gonna hurt it anymore tying to find out what it is.

That is a very interesting thought - thanks! The track was definitely much colder at that point in the evening and I'm sure they didn't do a very good job conditioning it this year. In fact, last week was the first night they opened up the entire 1/4 mile (three previous weeks were 1/8 only).

It may be a little tricky to try to replicate on the street around here but maybe I could trailer it out to somewhere quiet.