Stuttering at 3500rpm

[adam quantrill]

On the way home the car developed an intermittent stutter at 3500rpm on full throttle - most embarrasing when overtaking - I had to change up on a couple of occasions!

I am thinking ignition, probably coil, maybe ignition amp, I have two spares so I'll try substituting them.

Any other suggestions gratefully received though.

[convert]

When I had a similar problem on my 350 it turned out to be the central electrode on the dizzy cap.

PS The new Rad cap looks great