Last weekend I took 600mg of dxm (40 15mg soft gels) and when the effects started kicking in I injected 16mg of hydro over the course of an hour or so (small shots of 4mg each, spaced out over an hour).
I also washed down 50mg pf amitriptalyne somewhere along the way and made friends with a few balloons of nitrous.
I'm still alive.
It was quite a trip and I don't remember a lot of it. It's also hard to say how much of what happened is the result of which drug (would the same thing have happened if I only took the dxm)?
Now while I don't use dxm very often, I have a VERY high opiate tolerance, so the opiate part of the equation was unlikely to hurt me (but the results of interaction with the other chemicals is something I am ignorant of).
I do know that at one point during the night I started talking like Hunter S. Thompson, without trying to. Ive never imitated him before in my life and I'm not even a strong admirer of the man, but for some reason my tone and inflection began to mimic the famous drug user.
Very weird.
Anyway the point is I may have been 300mg shy of your dxm level but what I did is close to your question so it's relevant.
Also take note that I'm over 6 foot and a bit more than 220 lbs, so if you're only 5'5 and 150 lbs I would not use my experience as the basis for a thumbs up to your experiment.
Do a rehearsal dinner with half the amount you plan to consume the week before and see how it makes you feel. If a half-mg test goes well with no ill effects, you'll probably be fine.
Let us know how it goes!
Oh, one last thing - I spaced out my dxm pills too. I took 10 pills every 10 minutes until all 40 were gone - I figured it might be a good idea not to have that much crap hit me all at once.
Probably a good idea for anyone planning to consume mass quantities of anything.