Lifan old style Engine

Hi
Have anyone experience installing this engine on a st70.
https://www.pitbikeparts.co.uk/lifan-se ... -3802.html (I want the old style look and semi-auto clutch)

I want more power than with my 88 cc kit (Top speed 85 km/h) and have seen poor examples of 106 cc tuning on the original engine
The idea is tuning the lifan 125 engine (camshaft, ported head)

please share any comments ?

Grettings from Denmark
Lau