I think Mr Pascoe of MPL Sportribs is the recognised world expert on LPG conversions for OB's, they only rendered about 10 engines 'basket cases' up in Windemere back in about 96!
They were trying to get 2.5 efi's to run on it for a new LPG powered world water speed record, but of course they wanted them to run 'flat out' for 2 kilometres.
They rarely made the 1st pass without freezing the evaporator unit, losing gas supply, running lean as a result and going pop.
When they ran out of motors, and were also running out of Windemere week, they organised a crate of engines to be airfreighted from one of their US based OB dealer/tuners (owned by their team owner) When the crate arrived, flown overnight to heathrow, then helicoptered up to Windemere, all at enormous cost, to Marks horror the crate contained three blown engines that they had shipped over to the US the previous week for re-building! OOooops.