are you sure you're not mistaking the v6 issues of double row chain sets.
injected 5.0L is no different to any other 308 or 253 in regards to timing chains and being able to install a double row rollon set.
If you were changing to gear drive, you would then modify the oil feed. But that's not relevant to you. Nor is the fact the only difference in a holden 253/308 block would be the addition of a tensioner on pre HJ red motor.
Herp a derp it in champ, make sure you line it up properly by counting the links with the dots on the cogs sitting in the correct position as per your gregory's manual.
Hint, when blue motor came out with the extra pollution reg's they retarded the cam timing. If you want an easy 1-2 hp increase, use "red" motor timing cogs or a rollmaster type.