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.
Here at LandyZone we have plenty of very knowledgable members so if you have any questions about your Land Rover or just want to connect with other Landy owners, you're in the right place.