🦙 Ktm 690 Smc R 0 60

Where to find a big bore kit for a 690SMC? I hear that one of the SMC's that was built for the Pike's Peak race (uphill, public road, half dirt half pavement race from approximately 10K' elevation to 14K' elevation in the US) ran a 710cc engine. I've searched everywhere trying to find out who built the engine or where the parts came from w/ no 5hz2oDQ.

ktm 690 smc r 0 60