Bellhousing swap ? & Rv8 on su carbs lpg ???

In an effort to make my 90 more cope off road i have just bought a 1990 v8 disco 1.

I plan to take the engine and axles and mount them on my 90

The gear box im still not 100% on what i can and cant do.

I have a long stick defender lt 77 in mated to the 19j - this wont go on the v8 or will with a plate that means i need to mount the v8 well back ?

I have a short stick disco lt77 in the disco with the correct bell housing on.

Im not afraid to get hands dirty but before i go destroying 2 perfectly good known boxes is it fiesable to make a box that will work or just look for something on ebay But risk getting a johnner

Option 3 - loose the seat box and just extend the short shift lever ?

The disco has had an lpg kit fitted but never hooked up to the engine by the looks of all the new bits in the back seat still in packets. Is the 3.5 v8 any cope on lpg or is it a disaster with the higher temps ?

axles are no stronger just the rear has discs thats all both 10 spline. actually the 90 if its an early one has the strongest cv's lr made.

buy a proper gearbox if i see a disco box in a fender instant poor job bodge.

Ive been reading around and it does seem like thats going to be the best most reliable way, a recon box from ashcrofts doesnt seem that expensive but its wether i can trade in my boxes for a different box or buy outright. Rather than trading like for like.

Its the rear disks im aiming for jai my 90 is stock 86 spec , the disco axels are in much better nick than my axels my swivels are pitted and need replaced and the rest could really do with a rebuild.

The diffs on the disco have much less play in them than mine although mine have new shafts and drive member fitted already.