Hi jezza89,
the head gaskets are basically the same deign but made of different materials and are interchangable. You do have to remember that a composite gasket is thicker than a steel one so it does lower the compression ratio. Without going into the maths to give exact figures if you fit a composite gasket to a high (9.35:1) compression ratio engine made for a steel head gasket than you bring it down to a lower compression ratio engine. If you engine is already a low (8.13:1) compression engine than you drop it even further and loose engine performance. On the flip side a steel gasket on a low compression engine originally fitted with a composite gasket raises the engines compretion ration as does a steel one on a high compression ratio engine raise it high enough to require the best of fuels or a fuel additive to stop detonation.
The compression ratio can be found stamped on the engine block beside your engine number on the left hand (passengers side here in Aus) side in the middle between the exhaust manifold output pipes.
As far as I've read all Rover V8's up to the tempest engine were originally fitted with steel gaskets, the Tempest and early Thor engines had the comosite ones.
This of cause could have been changed during the engines life with a head shave and composite gasket fitted.
To identify your head there is a casting number in the rocker area in the centre of the head.
1976-87 Casting number - ERC 0216
Efi casting number - ERC 0216
Early 90's - HRC 2210
Tempest and Thor casting number - HRC 2479
It is common for people to put the HRC 2479 heads on earlier engines if the heads ever need replacing, they are the best finished with better air flow than the older ones due to better casting, they also allow the composite gasket to be fitted without modification and keep you original compression ratios.
I have the HRC 2479's on my 1989 classic and they were a bolt on replacement. Pthers out here may know if other year models lack holes for accessorys that there original heads had.
I can't remember however if the composite gasket gave allowance for the third row of head bolts below the spark plugs on the earlier engines, it's general consensus though to not refit these as it was proven that they caused head warping hence Land Rover did away with them.
I'm sure others can fill in any gaps or errors I've made here
Valguard


				
				
				
					
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