F1 to H1B Dual Status Alien Tax Question 1922542006-03-14 23:38:09

I’m on H1B about 160 days, and rest of days on F1 OPT last year. Am I a Dual -Status alien?
What’s ‘the substantial presence test on H1 visa’?
Last June, it’s 5 years I stay in USA. Should I file 1040NR or 1040?

Do you have any input on this?

I am more than willing to give more info if reqd.

Thanks,