Hi Les
Well you have shamed me into posting, not sure what model Quaife box you are looking at but i have been running the G60 as fitted to the latest R500, mine has the straight cut gears although i am told there is a helical gear set avalible.
The box is on the back of a Scholar built 2L Duratec with 250 bhp and i am running the 3.92 final drive.
From my perspective using the car for both road and hillclimbs its spot on, flat changes on the up shifts and clutch on the down,the change can be a bit more tricky when just driving slowly but I have improved the technique with use.
With all straight cut gearboxes its a bit noisy but its adds to the whole experience !!
Quaife would be the best people to advise on the ratios, but i have seen several of these boxes at Road & Race for rebuilds, i know they have lots of experience with these so will be worth giving them a call 01959 525105, good guys in my experience.
I have no problems with reliability but i dont do many miles so its mayby not a true test , the only mod i am aware of is the top breather which seems to allow oil to escape as the design is just a straight pipe with no baffle inside. ( easy Fix )
Price wise i have seen a couple of G60 come up for sale around 4.5K but its not often.
Hope this helps, drop me a mail if you want to have a chat on the phone.
Regards
Paul