The floors/trans tunnel/bulkhead aperture/seatbox/driveshafts/ configuration is all driven by the position of the transfer box.
The stock V8/5speed (also 300tdi) setup puts the trasnfer box about 2 inches further forward than the old 4 cylidner setups which is what you have.
Putting everything 2 inches further forward like that means the transfer box wants to occupy the same spaces as the front panel of the seatbox. Hence the different parts for the two different setups.
The v8/5speed/tdi setup also puts everything about 1 inch further to the right.
You'll need to (well, you should) weld v8 engine mounts to your chassis after cutting off the 4 cylinder mounts.
if you do that and try to keep the 4 cylinder floors, you'll need to weld the mounts 2 inches back. Then you'll need to mod the 4 cylinder transmission brackets to move everything over 1" to the right. But then you'll have to massage the 4 cylinder transmission tunnel with a ball peen hammer to make room for the LT230 linkage. And you'll have to fuck with the foam or it will keep you form shifting out of difflock.
Ask me how I know all this.
Bottom line, you can buy the trans tunnel and bulkhead adapters pretty cheap. You can modify your existing floors and seatbox to work. You'll also need driveshafts. The front one can be from any disco 1 and the rear can probably just be lengthened 2" by any decent shop.
Then everything will fit as stock and you won't have to futz around too much.
I have my old EFI harness out of the classic. Works fine.
Originally Posted by 85Red110
I suppose I'll just go about this the old fashioned way, and trial and error it until I've sorted out all the bolts. No problem though, I have time as im still waiting on parts to arrive. Also still need to source an ignition harness, figure out my pulley/belt configuration, get my radiator re-cored or replaced, and figure out if I'll need new trans tunnel and seat box to fit the R380. Any leads or advice will be appreciated.