I'd seek out a one-piece pipe if it was me looking. Lots of threads about the slip-fit/clamp-fit on the 2 piece requiring welding to repair. Unless you're running enormouse power, the sensus is that a 2 1/2" crossover will cost you bottom end throttle response, but flow better of course at the top end. When mine goes South, I'll be looking for a 2 1/4" SS one piecer.
HTH
Jim