... Any adivse on driving the ring would be gladly received!
... Looks like I'll have to pull it out and try and seal it again, any advise?
...2. It might not be providing enough back pressure hence not running very well
1) Drive slowly, that's quicker and better for your car. On easter it'll be full as hell and there'll be lots of accidents. Main problem is how to get through the traffic jams without overheating the engine.
2) The O-Ring around the water pump might have been damaged while you were installing the pump (too much brute force). Use a new O-Ring, use a little bit of grease and gently remount the pump. When coolant comes out of the pump's bearings, then buy a new pump.
3) Don't worry about back pressure. Worry about overheating tyres, about oil, bikers or both behind a corner in the middle of the track (had that a couple o'times), worry about your safety.
1. Couldn't agree more! I wont be going hell for leather, I want to have smooth safe fun!
2. I really blooming hope not! One thing I'm worried about is that when we took the old pump out it came out in multiple pieces, and had to be hammered/chissled out. Unfortunately in the process the block got a little scored. I've been in there with the emery paper and smoothed out what I can but it's possible the o-ring might not seal

When I put the new one in I greased the o-ring and the pump slid in fairly well. It did need to be tightened up to be seated so I did this progressively around each opposite bolt.
Well only one thing I can do! Pop it out and see what the situation is!
3. When we were going round last year the bikers did give me the bejezers! I'm a biker too and would definitely think twice about going round the ring. Bikes and Cars on a track at the same time is a little iffy IMHO!
On the exhaust.. I think the mid box is blown (it was old) so I'm off to get a new one and modify the exhaust tomorrow. May leave water pump till Friday

So a little more info on how she's running....
On idle the engine hunts, when cold it's impossible to get idle unless the throttle stopper screw is wound in some way. wide band reading is close to pure oxygen which i'm taking a guess is the result of the ICV playing up. Once hot it doesn't stall but still hunts for idle.
When running the exhaust noise is awful (which is the mid box being no good i think). She feels gutless under 6k rpm, feels like overfueling. We've only tried the wideband on stationary idle and when stationary reving which shows a lambda of 12 so overfuelling looks likely.