All 5.7 from 08 and down and all 6.1 have the same reluctor wheel. (Toner Wheel)32 teeth IIRC
The only difference in the two are the 5.7 has three bolts holding it on the crank and 6.1 has 4 bolts.
All 09 and up 5.7 6.4 and 6.2 have a reluctor wheel with 64 teeth. I know the 6.4 has 4 bolts holding it to the crank. I'm assuming the rest have the same.
I BELIEVE the only difference in the MSD wiring harness has to do with the early 5.7 with the crossover ignition wire and the 06 and up coil on plug wire. If you have the early version of 5.7 you can easily convert it to the later version.
So long story short buy the later version and convert if you need too.
Matt