Are Borg and Beck style clutches going away?

What doesn't make sense is why you can have less plate load with a diaphragm pp.

The answer is...you can't. The disc doesn't know what pressure plate is on it. It has no idea.

Back in the early 1980's we were using B&B plates with as low as 1900 pounds on rag discs.

My current clutch is a B&B/Long pressure plate that is adjustable and has a pressure range of 450-995 pounds of pressure.

So...if you can reduce the plate load on a diaphragm, you can sure as hell do it with a B&B and you'll have better pedal release and easier shifting.