Sorry guys, I'm a bit behind with my internet
The engine was a 3L with Westlake head producing 135 brake when installed in the original Rover P5. This conversion was carried out way back in the early nineties but I recall the lump was a direct fit to the 'box because the P5 block is the same as the original 2.6 (which in turn is derived from the P4 '100' 2625cc lump, being simply a short-stroke 3L) I think it needed a 2.25 diesel clutch but other than that it was a straight forward swap with just minor adaptations to accommodate the P5 dynamo & clearance for the air cleaner elbow for the LR's Stromberg carb, as I didn't get the P5's SU with the engine, which probably lost me a few horses but still left plenty to greatly improve performance.