Cheers - Simon and I are looking at options - I've asked Burton Power what was in the box they supplied- their very helpful answer was 'whatever was in the donor box' so could be anything as it was an outright purchase.....
Had a chat with Mike P last night and according to his instructions I need a 7T worm and a 24T drive. Apparently the 7T is the most common of the worm drive so fingers crossed I have one of those in, and just need to swap the speedo drive. I have a spare 25T one at home and will check to see what is in the old 4 speed box this afternoon. Knowing my luck I have an 8T worm, but I reckon it can be swapped out with having to remove the engine/box - just the interior.
Recalibration is an option, but 40% may be a little out of range, and I have read that is only alters the speedo needle and not the odometer which is the bit I use most. That could be a bit of internet bs though!
We're also going to experiment with a standard shifter - the quick shift gate is tiny and although I was doing OK with it, I think if I was trying to shift gears in a panic, I may struggle.
