Cheers Bob
I've bitten the bullet and cut the bottom rail like it says in the book, I really didn't want to but it got my gearbox another couple of inches further back and it misses the clutch slave cylinder.
I'm also going to have to make a custom sump for it as there is big lumpy bit at the front or I'm going to have a look at dry sump kits. But I've been making gearbox mounts today and will see what I can draw up tonight for a front mount.