500cc conversion kits

[jeffen]

I seem to recall, about 30 years ago, that there was a 500cc conversion kit for Mk1-5 and Dragonfly.  Are they a thing of the past or are there still some about?

[eddie]

As far as I am aware, there never was a 500 conversion for the Mark series. The 500 conversion for the Dragonfly was a venture by 2 members of the London Douglas MCC. They had special barrels cast to take Triumph Thunderbird pistons.
The conversion also entailed having the crankcases bored out to suit the larger diameter skirts on the new barrels. From what I am led to believe, all these barrels were spoken for many years ago.
                            Regards,
                                     Eddie.