I'm using a Mendeola 4 speed, a heavy duty copy of the VW 4 speeds found in the early Microbuses. It ain't cheap. I know about 5 or 6 SHO buggy owners and all of them thought they could get a "built" VW bus box and it would handle the SHO motor. Some of the guys went through 4 rebuilds and "upgrades" at about 1,300-1,700 each before they realized that the SHO motor + a heavy right foot = expensive transaxle repairs. As soon as they slap on a turbo or SC, the carnage happens at the next hill climb. My Mendeola costs 7,500.00 and withstands drag racing in deep sand.
I think I have one of those springs I think, if I do I'll send it to you. There is supposed to be some kind of pin in the front of the block for the spring to catch on. However, in your pic it doesn't look like there is any slack in your timing belt. Did he put a custom one on there?
Tom