It would probably be best if you only went for the Tech. Lead position if you have confirmed (and confirmable) management and people skills (to be honest, feeling that you "may be ready to take it on" is probably not enough -- leading effectively is a lot more complex than many people like to think, which is why there are so many bad managers who think they're doing a great job). On the other hand, if I interview someone who has skills I need that are not necessarily the ones required for the job applied for, I will suggest that he change his application and try out for the other position (if it's a job I'm also interviewing for, I'll switch the interview immediately; if not, I'll arrange an interview with the responsible party). I think that most people would do the same, so don't be afraid to extend your reach if you're sure enough that you have the skills.
