How about 150 shot and done?
As for being "done" -- with N2O you aren't backing yourself into a setup that would be costly the undo if you decide you're not exactly "done".....you could easily add heads + cam to the setup and would likely only need to address fuel pump and potentially injector swaps.
From my experience, a 150 shot on street tires can be a blatant waste of power because there's no traction to support it. I'm a M6 still rocking a 10-bolt with a 3.90 gear and run a Nitto drag radial. I understand that I'm way beyond the limits of what the 10 bolt can handle long term, however being smart about things has helped it make it along nicely for a while (most of my racing is from a roll, no hard launches, etc.). If you're spending a bunch of time at the track, I'd stay away from the 10 bolt + stall + drag radial + 150 shot combo if you don't have the cash in hand to swap a 12 bolt or 9" rear in when it finally goes.






