I'm rocking a spring loaded locker in an H one six five. In all fairness, it's a great wee invention, but it's just not up to the task for drag racing. see footage of me racing, I could see it open up during my staging burnout, but for fanging around the hills, it gives a pleasant two wheel push without the horrid-ness of a locky.
I began my H one six five locky today. The welded up spool I have had smaller bolts than the crownwheel. So I resized the holes to suit, and I'll slap it together tommorrow.

I've decided to get my 60ft as refined as possible before I hook up the nitrous oxide bottle. Theres no point in wasting it (given the price of the stuff) untill I have perfected the launch.