OPINION varies on the suitability of the Alloytec V6 for conversion to LPG. Holden is adamant that the engine needs the hardened valves and valve seats it fits to its LPG-compatible 175kW engine. Reports suggest that heads require rebuilds as low as 50,000km when you run the standard Alloytec engine on LPG. Some converters will tell you there is no problem, and that they have successfully converted a number of Commodores. The best policy would be to have hardened valves and valve seats fitted and a sequential-injection LPG system fitted.