[Toblahoe]

Update for any that are interested.

I "deleted" the flaps for peace of mind and the horrible noise went away!

I haven't noticed and difference in performance at all, and whilst I had the manifold off, I cleaned the intake and she runs so much smoother now!

Also noticed the oil filter housing gasket was failing, a decent qty of oil in the channel between the V, replaced that and cleaned up. Very time consuming job to be honest, entire thing probably took 12 hours over the course of a few weeks.