[skidlids]

As Jools mentioned I have my Hybrid which is a 748RS frame fitted with a 998Bp engine, both the frame and engine use 12mm engine bolts as standard.
I can check my 748R engine sometime to see if that has 12mm engine mounts.
You need a bit more than just the engine though, I also fitted the twin fan rad, oil cooler and pipes, harness, Airbox and repositioned the coils.