Well? IMO he would've supported it, though he might have had a hard time winning a Republican primary if tea partiers got hold of Ronald Reagan's fiscal record as President or Governor. I think though, that he would've been ideologically in sync with the tea party (economically anyway), though his record might not show it, at least in the balanced budget part (governing as an economic conservative is very very hard to do).
I think he would have appreciated it, if something like the tea party had come up in 1978 or so.
Reagan is the kind of guy who would held the wide, but shallow Republican coalition together. The tea party would have been another cog in that wheel.
A lot of it is luck with timing.