Would be kinda impossible, You would have to make your own V12 Block, and also make at least one head, as you would need the exast outlets to come out the outside of the engine and both inlets to be coming out the middle.
....Would be cool though.
What would be better is one of the 4.7lt petrol Nissan straight 6's out of one of the new Parthfinders, there are kits for a 5.3lt stroker, and crazy Arab's are running around in Sand-Land with 1400hp versions blowing Lambos away in their 4x4 trucks!
The development of the v8 motorcycle engine in NZ, 2 x kawasaki 1200's on a billet block, they initially ran one head reversed and a separate shaft through the block to run the cams off the back of the engine on one bank...
So you would only need a custom crank and billet block ...
But , dumb idea anyway as there are easier alternatives.
This is the latest rendition