I installed some cutting brakes on the rear axle (using electric line locks). The disappointing thing is, they don't work.. That is to say, they do hold pressure (1100-1200psi) at the caliper, but it is not enough to keep the wheel from turning. The disco will drive right through it at idle in low range.

So what are my options here? I am considering a hydroboost conversion, which could develop as much as 2000 psi, but the install is a PAIN, and I'm not convinced that the Lockheed calipers would stand up to that kind of pressure long term.

I guess then I need to find some bigger calipers to go on the rear. Anyone know what fits, or is close? I don't think I have seen anyone put a different caliper on a Rover axle before. Needs to fit inside a 15" wheel, also.

Plumb up some 4 pot front calipers.
With twice as many pistons you'll give twice as much clamping (and stopping) force.

They'll fit within a 15" wheel, but you'll need to make up some brackets.

they will hold, Ive been running my boost for almost 2 yrs, no probs yet.

DOOOOO IT! its about a 6 hr job

Line locks suck for cutting brakes. Put a proper cutting brake into the system and you'll be much happier.

Or just learn to power brake.