Factory fuel pump

Its not a matter of performance, its a matter of having the correct pressure. The early Hemi's are supposed to have 48 psi +/- 2 psi and the later model ones are supposed to have 54 psi(off top of my head, might be 58) and typical LS type is 65+. Lots of people running Ls and may not have problems but I have seen some with problems. I am a stickler for things being correct. I would not worry about it if I was running a 6.2 or 6.4 but you can definitely get drive ability issues with earlier 5.7 like injector drip, rich condition codes etc. We just like to do things right and prefer a Mopar part over a GM. Its also less money!