Realistic valvetrain expectations.

you mentioned using tbi yet the good hp ls engines are all sequential injection with the injectors in each port of the inlet. that allows much more precise tuning for the power/drivability they make. i'm unsure why you're against increasing stroke at all. as andy says you can do it at 400 ci but you won't like it on the street. it won't be ls driveable for sure. also why do you need to rev to 6500 if you don't need to to achieve the required power goals? the ls has a much stronger block architecture (that 40+ years development thing again) with crossbolted mains etc than the mopar so revs are safer/more reliable. it's not an ls despite any suggested similarities, so just treat it as what it is and carry out any tuning accordingly. you can and will achieve the power you want but in a big block mopar way not an ls way. :thumbsup:
neil.