Ahhh... Finally !
Shopping/to do list from begining to end the way I see it:
1.5 8V dizzy
1.5 8V back plate (to use the mech fuel pump)
1.5 8V flywheel
Custom radiator hoses (or just flexible ones)
P4 gearbox tail and gear lever
P4 rear axle and propshaft
P4 Handbrake cables
Extremely SHORT rear springs and matching shocks - otherwise you will lower the car and find out that the rear end is taller than a Pajero !
Wheels with very little offset
Remove fuel tank
Cut off spare wheel well
Cut off section of the cloor panels that the pervious gearbox used to bolt on
Cut off rear chassis section underneath the rear seats to make room for the P4 strangely shaped panhard rod to move up when the suspension goes down
Box in and reinforce chassis bits
Drill out new holes to mount the rear axle with diff - I reinforced it with a piece of pipe going through
Make new mounts for the gearbox and propshaft
Find a way to install a fuel tank
Fabricate new exhausts.
Gearbox work prior to installation:
Take the tail of the gearbox off, before mounting it on, and remove the magnet in the viscus coupling, drill and tap out some threads, permanently engage it with 4 bolts and spot weld them into place.
Remove the front diff completely to save weight and friction.
Either put the drive shafts back in the gearbox or make plates to shut the holes.
Dont forget to take apart a set of front drive shafts, and use the outter sections only to bolt on the front wheel hubs to keep the bearings from coming off.
Take off the radiator, find a 16v radiator, cut a section of the front skirt of the car (it wont show with the bumper back on), and bolt on the radiator from the outside of the engine bay.
Better for cooling your bigger engine, more room for the radiator fan, more room for the belts etc.
Be sure to mount the propshaft as straight and as aligned as possible to avoid vibration as much as possible.
Loads of work needed and many hours, but defo a great result