More sporting gear ratios

[Julian Caples]

Lewis

Bristol made a number of close ratio boxes (all with higher first gear) for racing. Early Frazer Nash boxes (to go with FNS engnes, contemporary with the 85/85A/85B/85C engines) were CR3 type.
Later (Borg Warner synchro type) were BWCR6, BWCR9 and the BWCR12 mentioned below. they all have closer ratios (which will sort out your large gap between 1st and second and third) and a higher first gear (with no synchro)

the other implied problem in your question is your overall highest ratio. this could be dealt with by either and overdrive (use the adaptor kit and more modern overdrive to fit inside the footprint of the normal Bristol gearbox plus extension) or a higher final drive (a 3.66 ratio was used on some cars - normal 400/401/403 ratio is 3.9, 405 final drive is 4.2 with overdrive giving an effective 3.3ish ratio)

none of these options would be cheap, but they would be historically 'correct'. Rob McDermott can probably help you if you want to go the CR gearbox route

the ford option could be cheaper

cheers

Julian