All factory 5.7 top end engine parts, just about everything above the head gaskets (needs 6.4 head gaskets) is factory 5.7. I did not tune anything, it would set lean codes with the 5.7 injectors so I got a set of fleabay used 6.4SRT8 injectors and no more lean codes. The 5.7 and 6.4 TRUCK engine use the same injectors you need the SRT8 injectors.

It results in more cylinder pressure with the small cam and small chambers of the 5.7 heads, I put the ex valves in the drill press and mirror polished them to keep em from being as hot. There is no sign of detonation on the plugs, audibly or on the knock sensors in the data stream even on 87 octane.

I bought a set of long tube headers today on craigslist that hopefully fit and give me even more giddy up, Ill post up the results if they fit.