Upgrading the 410 Final Drive Ratio

[John Keighley]

We are in the final phase of major work to our 410. Among work being completed is: Engine rebuild including upgrade of the camshaft, electronic ignition, replacement of the Carter AFB with an Edelbrock AVS2 500. Addition of aircon (410s have no adequate internal ventilation and are utterly suffocating in Australian Summer conditions) and a long list of other improvements. With the engine upgrade, I want to raise the final gearing to lower the cruising engine speeds as to me, for an 8 cylinder, they seem ridiculously high. Current differential ratio is 3:07 (same as the 411, I believe). Has anyone in the group with a 410 raised their final drive gearing and if so, what specification?
Thanks, John K.