I think the change over from 3 to 4 bolt tone wheel was in 2016, I hooked up my builder up with a pai of police 5.7s both were 2015s , both had 4 bolt tone wheels, but the 5.7 in my daughters 2015 Challenger had a 3 bolt. all were 58 teeth.
you can use the 6.1 wheel or any of the aftermarket 32 tooth wheels.. My sons 08 2500 has a 2016, 6.4 in it, had to change the tone wheel while we were in there we did bearings and a new pump left the cam stock , we locked the cam at about 10 degrees retard from the full adavance postion. . had to use the 2016 front cover , mounted the Stearing pump where the 16 had the alt, and mounted the alt where the 16 had the air compressor , he did away with the air condition compressor before he swapped the 6.4 in.......Also FWIW , my 2010 Challenger stroker motor(408CI 4.03X4) is a 03 5.7 block and we used the 2010 VVT front cover....bother VVT and Non VVT timing covers will bolt on to all 5.7s but the older cover won't clear the VVT cam system. both cover have the cam timing sensor in the same spot and relationship to the tone wheel(on the cam gear ) is the same depth.