Hi All,

I'd be inclined to say that it's the original power plant (as Mod CJ has suggested).

I would strongly recommend you look for any stress fractures radiating from the mounting holes in the chassis. My reasoning for saying this is that the clutch has been at some stage replaced to the current style unit with the 2 90 degrees opposed grub screws. When these clutches are fitted it is for a reason, and that is the previous clutch half was flogged out and in the process would've induced some vibration into the chassis. The twin railers were so prone to suffering from this issue and thus why I'm suggesting you have a good look before going overboard. This isn't a hard thing to solve but it must be done as it will lead to terminal failure in the long run.

Cheers,
BB.

I live a 24 Hour lifestyle, but every now and again I seem to fall asleep, well at least that's what my wife tells me.