You can buy an adapter like edog did when he put that engine in the atc90 frame. Or you can drill different holes. The lifan is based on the atc70,z50 engine cases and it is smaller than an atc90/110/125 engine.
Nicholson 500x (Project)
Nicholson 185s
Nicholson 110 (That takes an atc70 tank)
Ascott 500 head/350x (Project)
Homebuilt Racer Chromoly Suspension 110 (Ragin Runt)
PK Racing Suspension 70
A+ Inc Suspension 70
AWS Aluminum 90 frame
Hi Performance ATC Suspension frame rd350
Hi Performance ATC Suspension frame 90