Wow, 69 mph on a 44T rear ! That's revving on
Mine is still on a 44 at present but feels unhappy at 55+
As I have gone to a 100/100 rear tyre I have a 43T to go on soon.
There is a great exhaust/silencer guy down south in the UK. Not sure where yoare Giler.
I must get my finger out and convert many of my spare engine bits into a decent motor.
The megacycle cam and head is begging to be fitted to a modified lump.