Yes! The Buck215/RoverV8 was originally a very messy engine. AI Google it! " did the Rover V8 have a reputation for leaking?"  You can substitute Buck 215 for Rover v8 if you wish to know where it all came from.  Oil and coolant leaks everywhere with a bad habit of overheating. However, the original, revolutionary geometry at the time was great. And happily, as with so many things that last long enough, these faults improved mightily over decades. My LR,  Rover and Buick 215 V8s became spotless using the improvements the Rover/LR managed over more than 40 years. Better seals, better gaskets, smart tweaks. I tried to keep up with them and the csavvy community before them and my engines became dry. However, I still sadly see owners of these earlier engine struggle with components and methods that were done away with by the mainstream many decades ago. These needed changes are costless or very inexpensive.    

THE SWITCH FROM AN OVERFLOW COOLING SYSTEM TO AN EXPANSION

One of the original problems was the cooling system. It made a joke of the early Plus 8s and the Rover P6 3500s. The MMC even recommended that we jack up the rear of the car high when topping up the coolant! A very curious "swirl pot", suspended above and to the rear of the rad, to fill the system. First time I visited the Works Pickersleigh Road (in 1974) they had a pile of these removed thingies they had stashed in their returned parts corner. After their experience with them, they removed them whenever servicing a Plus 8. Does any pre-1976 still have them? Wanna get rid of it and reduce your cooling system hassles? Read on.

After 300,000 miles and many Plus 8 engines, I can assure you, overflow/recovery systems are a PIA for our engines and engine bay configuration. Rover removed the swirl pots in 1976. Then Land Rover changed to changed to an expansion system, concurrent with the advent of the 3.9. Savvy owners changed before that. The switch costs nothing. I learned to retro-change all my engines (5) to expansion systems on arrival.  

Merely as a background for the newly initiated, :)

An overflow system keeps the radiator pressure cap on the radiator. The overflow tank is not really part of the cooling system. It can be placed anywhere. On a Morgan Plus 8 it makes very difficult to rid the system of air bubbles.

An expansion system keeps the pressure cap on the expansion tank. It must be placed above the radiator. (shrug) Plus 8s traditionally site the tank on the bulkhead, far enough away from the rad to be cooled. 

There are practical advantages to expansion of overflow. 

1. It effectively increases the size of the cooling system. A cooling system size is determined by what is pressurized.  

2. It ends the ritualistic silliness required when changing or topping up coolant. An expansion system allows the system to pleasantly vent air. Merely fill the system the best you can and then the fill the expansion tank up to 2/3, drive around for a day or two and take a look after. If there was too much coolant it will have disappeared. If there was too little, fill it a bit again to 2/3 again. You are looking for it to settle at a permanent level of 1/3, showing that the hoses to the rad are full.  

3. It allows Morgan owners a safe possibility of depressurizing when hot. I can do so immediately on stopping with a hot engine merely using a rag. 

To change to an expansion system merely swap the pressure cap on the overflow tank and use the Rover/LR blanking cap LR part# GRC126 on the rad.. It is the same cap and system used on the Austin/Morris/BMC: the 1100/1200 derivatives, the Vanden Plas 1100/1300, the Jaguar E-Type (Series 1.5 and 2), XJ6 (Series I, II, and III), and the XJ12 along with the MGA Twin Cam..all from the 1960s. Others realized the advantages of an expansion system early on. You can find such caps to fit everywhere.  

PLUS 8 COOLANT SYSTEM PRESSURE CAP

On another related subject. I do not play around (aka cover up) symptoms of engine problems. Symptoms happen for important reasons. They are the car's way of communicating with you and more reliable than diagnostic devices. In the case at hand, boiling over should not be cured with waterless coolant (i.e Evans) or a higher pressure radiator cap any more than mechanical noises or bad backfires should be cured with ear plugs. In the case of Rover/LR Plus 8s, the cooling systems water pumps, hoses, hose clamps, gaskets..the entire lot designed for 15 lbs pressure. Why stress it all with an extra pressure? Why ignore a too hot engine completely with waterless coolant? All my engines, whether stock or tuned 3.5s. 3.9s, big muscly 4.6s or a 4.8 run run in all ambient conditions at 15lbs without an overheating. If anyone needs help with that..ask.