not really due to the abs system/body control module etc. It can be made to work but takes time and money. Better of getting a vs computer/harness etc. Since i havent done it personally thats all the info i can provide.
If u dont go with the idea let me know about the v8 vn for cheap. hehe
You can put any motor from a VN into a VS 1/2 and back the other way around no problem as they all run the same emissions law. As for the loom that will depend on if you are using a VN manual/auto or a VR+ electronic box
I think what you're getting at is "Does the VN engine harness mate up with the VS body harness"
When I done my conversion from auto to manual, I bought a new VS engine harness to suit the manual computer.
I specifically had to buy the VS version of the harness because of the placement of certain plugs in the engine bay. I think the VR harness has a plug connection near to the battery, which in the VS engine bay is up tucked in behind the r/h strut tower. (same connection, different location)
If I bought a VR harness the plugs wouldn't reach. (or conversely if my step-dad bought a VS harness for his VR it wouldn't work out.)
If you've got both cars, have a look at the locations of the plugs.
I found my local TAFE had VN workshop manuals and I could use those to see what wires in a certain plug went where. So, effectively, find out what the orange/white wire in pin 1 of plug "x" goes to. Then have a look at the same plug of the other car and see if the same pin (probably different color wire) goes to the same part. If they all match up, you could be on a winner.
You can probably extend the wires without too much hassle. (Use a soldering iron and some heatshrink tubing for each individual wire, and then re-wrap the loom with electrical tape)
There are small differences that I noticed from lookign at the VN workshop manual to my VS harness. ie: In the VN there apears to be a short "transmission harness" for the manual. On the VS harness the wiring for reverse and speedo are not seperate from the engine harness.
One final thing to consider is that I haven't looked at the V6 harness at all. I only done a transmission conversion, not an engine conversion. I can't see that they would go to the expense of making different body harnesses for V6 and V8 though...
What you may find easier to do is buy the VS 5.0L engine harness (as rian suggested). I live in Newcastle and Holden Spares had to order it in especially from Melbourne, but it is still available for around $150 ish (or was, about 8 months ago when I bought mine)
All said and done, I have a VS engine harness and a VN computer, so it's compatible in that respect.
The harness saved me a lot of hassles and was money well spent, in my opinion.