Vixen diff ratios

[Monkeythree]

My Vixen is still running the 3.89:1 Triumph differential that it had when it was new and had 89 Bhp. But now it is running ~125 BHp I feel it would benefit from gearing it down a bit.

I want to keep the differential casing/mounting "original" i.e. Maintaining the existing chassis mounts so this means my options are either 3.63:1 or 3.27:1. Does anyone have any experience of running a modified Vixen with either of these final drive options?

[Monkeythree]

Thanks to everyone for their inputs. I've decided to stick with the 3.89 and enjoy the acceleration!