I believe Jays (who used to be on here last year) had the conversion done at Henry Williams place and he was pleased with the result. I'm pretty sure that's what he had done but it was a long time ago now and the memory bank is not what it used to be.
If I remember correctly he wished he had hung onto it instead of buying the Roadster which he didn't keep for long.
Probably worth a call to Henry or Lawrie for a chat. There is a thread on here by Lawrie (Chunky4/4Racer) all about the race preparation of Henry's racing 4/4 Sport which we all enjoyed viewing.