The SRT sporting the same size motor but some adjustments give it 475 on stock from Mopar. On 2017-18 Valves are the same size between both motors (2.138/1.654). Compression is lower by about 1 point, 10.9:1(SRT) vs. 10:1 on the Ram. Apache head design is basically the same for both motors except for material (356 Aluminum on the HD) and redesigned cooling jackets. Tech Authority lists the cam lift and duration for the HD motor, but at a glance it seems unlikely to be 100% accurate. Especially considering they appear to mimic the SRT cam specs. The truck 6.4 has different heads, cam & intake manifold
Throttle body however is the same on the 5.7, 6.1 & 6.4
So it leaves the exhaust to make up some hp.
Then tuned to speed up timing some more to run 93 octane