i'm a bit too far mate sorry. Changing your gearbox ratios isn't going to correct the problems you think you have. If its that slow your engines knackered or needs setting up right.
I had a gearbox built by Bears, was around £800, lots of money but it drives great and 6,000 warranty
I've been out in it tonight and had a good drive, 44ish changing into fourth, steady at 60 mph, not massive speeds but within the speed limit I reckon I'm gonna put up with the whiney noise for a w hike til a six rib comes along. Running really well, tempted to have a long weekend away haha! Thanks for the help and comment from Joker
The thing that'll quieten it down the most is stuffing under the RR bed with anything you can find - a canvas awning works a treat.