mustang bolt ons help me out

i found out that i got 327's so anybody got 410's what rpm do you run at 80? i wouldnt want to go that low if it is way up there and thinkin about getting a stall converter would 2800 be to much for stock axles and with the stall what would you reccomend me doing to the rear end while i had it apart bigger axles? locker?
please help me out and wanting to get offroad x pipe and what mufflers should i get i got flows on it now what do you think sounds the best i just want it to sound nasty you know what i mean well badass i heard slp sound really good ans long tube headers? you guys think that would be a good setup? so long tube headers offroad x pipe 2800 stall converter and 410's or 373's what do you think i would run after i got a tune possibly 12's? or 11's?