Looks like we're all thinking pre-2000 as a general consensus then?
I can't see anyone turning up with a 5.5t motor and an ESC with mad timing to run vintage, if they do they've missed the point!!
I'll bring the 17.5T along Barry, it would be interesting to see a vintage buggy go with it just so we can see what to expect. Do you have any connectors on your ESC -> motor or just soldered straight to the motor?
I've got an Axial 27T brushed motor that can be used for testing as well - I must admit though, I've only ever ran that and the 17.5T on 3s lipo (rock crawler) so I don't know what to expect!