The tank may be ok, but I am unsure if you have a fuel pump in the tank that you may have to remove and extend the pick up pipe (somebody help me with this)?
You will need a flow and return to the tank which the V8 probably has, you will need a fuel filter head on the bulkhead, the V8 IIRC is very light so the front springs may need changing. Air box and other odds and ends may be different, I am unsure about the radiator/oil cooler, gear ratios in gearbox may be different. Temp sender may be different if so get the V8 one into the diesel.
It is best to buy a rotten/wrecked donor car with good mechanicals as you may end up running back and forth to the shops/breakers for bits.
Is an LPG conversion out of the question?
regards
Dave