[my69gto]

I want to add posi to a stock single leg 69 GTO 8.2 rear. I was planning to go the aftermarket Eaton route, as a fellow PY'er pointed me a great deal (thanks pont406!). But I thought, before I spend the money, is that the best way to go or is a factory 4 pinion a better choice? This is for what will be a primarily street driven car with 3.55s most likely (although I haven't ruled out using a set of 3.90s too at this point). The engine/trans will be a mild 428 (+/-400hp) with a T-400. My thoughts are that I don't want to worry about leaving pieces of it all over the inside of the housing if I indulge in some spirited driving...which was the result of my old 2 pinion one.
Input pros and cons is appreciated.
Dave