Hi ,

I had an L8 was always on the high side ( better for the turbo then to lean ) .

Was your basic rpm the same when checked ?

Colour from your spark plugs are also important there I think a lot of these aftermarket gauges are not good calibrated there my spark plugs were showing slightly brown what should be OK.

Afterwards I installed close loop from MSD and the needle was dancing all the time trying to adjust

Steven