The point missed here by some dummies was that just because a design is old does not mean inferior, and the bit about cossie engines was called sarcasm.
Cosworth did such a wondefully good job that the engines were having head gaskets changed when undergoing NCH test at southamton uni on std power, NOT raised power levels.
The main changes as ever was due to a shit design of cooling system, the reason it changed on subsequent versions, nothing to do with power at all, the changes were what they should have done to start with.
tabetha