Wow !!!! That would be an interesting conversion !!!!
Ok, I will just dump as much information as I can....
Front SeatsThe front seats will be fine with the exception that there will be no cabling for the colour screens for the headrest.
The front drivers seat on the Caprice has a memory function, which allows the seat to move around based on the last
key memory position that was used. (I.E. the seat will adjust itself to the last used memory position set with the key that is used to unlock the car)....
If your HSV doesn't have this function (I.E. Drivers memory seat), then you will also need to add a couple of cables to connect to the SW Can Bus, so as the memory seat module gets its commands to do its thing....
If you don't wire the above up, then its no biggie, you just wont have the seat adjust to the last position used for the selected key...
Back SeatsThis MIGHT cause you some dramas....
On other makes and models (I.E. Fords in particular), the side bolsters on the back seats for LWB models are much deeper than on SWB models...
This means (On the Ford Models anyway), that the bolsters will stick out more, and wont match the door profile properly...
This would be something that you would need to check before purchasing the trim...
Next the rear seats have ??? I think ??? the triple zone climate control panel somewhere. (I think in the armrest ??? Not too sure)...
If you wanted to go triple zone climate control, then thats going to be a mission in itself. (You will need to change the headunit to the Caprice model, get the HVAC HCE from the Caprice, and do lots of HVAC airbox mods to get this going)....
To be honest though, I dont think you would be too concerned about trying to get Triple Zone Climate Control working...
Roof Mounted DVD PlayerUnless you have the Roof mounted DVR / LCD screen fitted now, then there will be no wiring for the Caprice model.
(The caprice model is slightly different to the HSV/Calais V/SS-V models, in that it is supplied by BOSE, and the SWB models are supplied by Blaupunkt... So wiring may be different as well....
Other Trim BitsCarpets and roof linings will not fit. (So if you didnt have the Roof Mounted DVD player, you will need to get a roof lining from a SWB model to fit this up).
The Caprice BOSE stereo will require the Caprice dash trim pieces to fit...
(Not too sure how many pieces or what is required, I will need to research a bit more).,
Also the Caprice radio would need the VIN programmed, and the climate control set to Dual Zone, and not Triple Zone.
Instrument Cluster would require the upper dash crash pads to be fitted, and probably most of the dash plastics to be changed over to caprice... Meaning that you would loose the HSV Triple Gauges, so this may not be worth the effort....
I hope this all helps !!!
Definitely let us know what you find more information, or please ask more questions if you need more information !!!!
This is definitely the type of stuff that most of us are interested in here, and would be well up there in the "That's Seriously Cool" things to do !!!!!
Oh and welcome to the forums !!!!
Cheers
Matti