The ONLY head gaskets I now use for the Rovers, are the Cometic, because, everything considered; practically speaking, they are vastly superior to ALL other head gaskets from all other makers---the majority of them being junk, with a limited life span. Why waste time and money changing head gaskets, when you can put the best on, and, if you do your part, in seeing that your heads meet specifications, and are not warped beyond factory .002" tolerance (if they are, having them skimmed by machine shop), so they are flat within .002", you probably won't have to do the job again? I don't sell Cometic, or have anything to do with promoting them, but I do feel free to state the obvious, that they far exceed any other head gaskets by other makers. Jags auto parts, in Ohio, sells them for Rover engines; sometimes they have them on ebay; they recently got an order in on them, for the Rover engines. Cometic cost more, but are worth every penny. Why do you suppose that most Rover owners change head gaskets so often? Obviously, it is because they are using common junk head gaskets, no doubt about it.
ARP studs/nuts are also vastly superior to the damn stretch bolts that Rover, and so many other auto makers sell for street auto use too. The stretch bolts put too much excess stress on the aluminum block head bolt holes, because of the thin aluminum between the block water jacket and the cylinder liners. That is proven by the very high number of hairline cracks in the block, that occur, most interestingly, precisely at the base of the head bolt holes, usually following the engine being overheated too much. After that, one sees the liner where that crack happened, loosening up and "slipping" up and down. Coolant from the crack, gets between the liner, from the water jacket, so when liner slips upward, it is not secured at all by most head gaskets, but the Cometic does somewhat help to stop the upward movement, though the coolant, especially over time, moves from the hairline crack downward, into the oil pan anyway. I have rebuilt these Rover V8s since 1970, when I had that engine in Rover sedan. Best, Jack