Bore has no lip and i checked ring gap every time i had it apart and was always on the higher end of the spec, installation is not the issue either.

I think it may be detonation which is realy hard to hear over the engine and exhaust.

Rallytwit. How much total timing did you run with that much compression?

Once im done woth this new build I will stick to 98 octane to be on the safe side.

Maybe 30 degrees of timing would be safer than 32?

Compression will be around the 10.1 mark.