Thanks for the usual illuminating response Firko, it alway surprises me the amount of energy that goes into any HL discussion, I see it as being a bit like talking Harleys with unbelievers, the most strident critics tend not to have owned or ridden one.
Back to the Pro Tec TT600 that started this thread, the value of the engine has been over looked a bit, the original ProTec bikes were bored stroked, Jerry Branch ported, there are claims of close to 60 horses.
Which makes me ponder my dream HL500, probably OW forks and wheels, GMC frame, Bengt Abergs 3 valve engine