Some comments on 5 speed conversions - something I have done quite a bit of homework on recently!
This as seen from the European perspective.
Over here the popular conversion uses the Ford type 9. It's plentiful, very cheap and pretty strong. It also has a detachable bell housing.
There are several UK companies selling conversion kits. These work by fitting an adaptor between the original Triumph Bell housing and the Ford Box. Uses the Triumph clutch setup with a different friction plate to match the Ford splines. You need a new propshaft and there is some messing with mounts, speedo cables and transmission tunnel - but basically quite straight forward and reports of the finished article are very positive.
See link to Josh Bowlers website, he's done it and likes it.
For those in the US, I understand the main drawback is a lack of Type 9 gearboxes.
For me on the other hand, the drawback with this conversion is that the type 9 is long and has the gearshift right at the back. On the Vitesse this brings it out half way down the handbrake! You can shorten the shift a bit but not really enough.
There are not that many alternatives in the UK as most cars with RWD and 5 speeds have gearboxes with integral bell housings (BMW, GM, Mazda, Nissan etc) and this makes things harder. There are some nice gearboxes in the Toyota range, but not very many RWD Toyotas left in the UK as most are old and rusted away years ago!
The T50 as used in old Celicas and such is a great box but rare here. Maybe better in the US. The W series boxes as used in the Supras, Cressidas and 2wd trucks is a good box but rather wide. It is available here though and that is what I have been looking at.
I have a box (W58) from an 3.0 Supra. It has nice ratios, is shorter than my O/D box (just) weighs about the same and should be unbustable.
There is a conversion kit available from Dellow in Australia - but you need deep pockets!
My route has been to cut the engine side flange off the Triumph bell housing, cut the Toyota one down to get the correct overall dimensions for the input shaft and clutch to work and weld the two together. If you are careful where you make the cuts they are almost the same diameter. I'm using the Toyota clutch release mechanism (hydraulic) and a 215mm Toyota clutch plate with Triumph Cover. Some fairly minor mods are need to the chassis rails as this box is big. The Toyota propshaft is a snug sliding fit inside the Triumph one so that is quite easy.
I'm not done yet - I have to finish the bell housing mod and modify/change the shift mechanism to move it forward, but it's looking good.
1. three gearboxes, Triumph with J type O/D, Toyota W58, Ford T9 (with vandalised shift!)
2. Bellhousing mods - that black ring on the bottom is the jig I made to get everything concentric.
3. Trial fit, pretty much in position - plenty left to do.
'67 Vitesse Mk 1.5 EFI
'65 Herald 1200 '13/80' Now sold again - gone to live in Perth WA (!!!) with Mr Thompson!