For those of you who have upgraded your engine output, by over-boring or even supercharging, there is a simple upgrade that will make your clutch stick better without having to resort to the calf-punishing of a performance or race clutch.

Read more at …… http://bradleyrestoration.com/technical_resources/mgb_clutch_upgrade/
The picture i have shown of the TR clutch disc certainly looks more beefy than the standard MGB clutch disc.
The only question i have on this “theory” is that although the TR clutch has more area but it is still the same spring pressure but applied over a wider area making less force per square inch!!