1jz harness modification

[Surffer227]

For those of you with jz swaps or that have modded a harness for an s13 before, is this really as straight forward as cutting the harness and extending each wire like a foot or two, one at a time? I'm starting to consider pulling my harness off the engine and putting it on a bench and just duplicating it but longer, if there is more to this (other than speedo and tach) can someone chime in? Or maybe refer me somewhere that might have this info? Other than comparing fsm to fsm. Thank you. This info is very hard to find since everyone outsources the harness, which I may end up doing.