You know it really comes down to what you want. There are 5.0 guys and mod 4.6 guys. Each swear their motor is better or easier to build up vs the other.
For a while 5.0's had the parts market by the ***, but in the past years the 2v mod market has grown and is right up there...just look at the options for h/c/i for a 2v online.
5.0's are really for the backyard mechanic that loves to tinker with his engine. the 2v's are great for throwing on some heads and a blower and calling it a day.
Reliability comes down to the application and whether your not pushing the limits of the block. The 5.0 block's limitied to around 500hp. The 2v's teksid block is strong, but the rods are only good to ~425-450ish.
12 Black GT500 SVT PP l 2.6 Pulley/Idler l Airaid l o/r X l 305 NT555R's l Recaros l
04 Azure Blue Mach 1 / 03 Sonic Blue 3.8 / 14 Sterling Grey F150 FX4 402A 5.0 / 11 GT500 R.I.P.