Oh it's an older one, not the 286kw one or whatever? (not 100% upto date with LS1 outputs in whatever forms)
You basically get scrutinised for everything from Emission controls, brake/drivetrain upgrades, engine mounting, frames, exhaust noise etc etc. IIRC as soon as its non-factory, non-family option - you go through the ringer.
I think more than a 20% or 25% power increase it gets tough and the other issue is the torque figures will be what will really hurt you.
EG. You can't engineer a LS1 into a torana or anything these days here. The VASS Engineer who did my car (26 into a HR) was telling me it happens often as people do the conversion BEFORE checking with a VASS signatory. They haven't signed off once since some changes were made a few years ago. Not sure what they were though, i didn't go into more detail on that topic at the time.
Cost/Effort wise it's a certainty you'll get a RB in, and cheaply simple due to the fact it's Nissan and it's bolt-in effectively with just a brake upgrade to the same or similar spec the motor came from.
Fken Victoria is seriously 15 years behind. The EPA laws are from 1992