Agree with Keith and Arwyn. It is the best mod I've had done - cruising is comfortable and I'm getting mpg into the high 30's.
I had the modification done by Simon (SiFab) as I don't have the space at home to remove an engine.
I bought a full recon box from Burton as I wanted some form of guarantee/comeback. I kept the standard gearing (you can get a longer 1st gear) but it cost more (and my budget was tight) and I can't say I've noticed any problems.
As Arwyn said, Simon had the original propshaft shortened.
Burton couldn't tell me what speedo drive was in the box they supplied, and it turned out to be well out, meaning we had to strip the box down in situ and fit the correct one. We should have checked first, bt hindsight is a marvellous thing! I've used the ratios provided by Mike - speedo reads about 8-10% under but that could be exacerbated by the targer wheels/tyres I use. It's close enough for me, and I can't be bothered to fanny about anymore with the gears.
