5 Speed Box?

[triumph2.5pi]

Hi all. I used to have a T25 with a 5 speed 'box. I remember to all intents and purposes I used it as a 'normal' "H" 4 speed as the dogleg 1st was so low I found it mostly wasn't really needed.
Now I have a 4 speed T25 with a 1.9 engine that needs replacing. I'm going for either a rebuilt 2.1 or maybe even Subaru. In any case, I wondered whether it's possible to also change the 'box for the VW 5 speed, but change the final drive ratio to something higher that will give me a more 'normal', useable 5 speed box? in other words, 1st be a more 'normal' ratio and 5th be an "overdrive" motorway cruising gear?
Is this possible, or am I barking up the wrong tree?



 

[Aidan]

Gearboxes are built to match the engine(and vehicle), the original gearboxes matched the original engines (and vehicle intended use, so for example the van with a KY 1.7 n/a diesel was generally geared as a round town work horse and isn't great as a motorway high speed mile muncher), if you put in a more modern engine then yes you can have a box built to suit it. Different final drives and alternative gears for the taller gears are available.
As well as the original gearboxes being rebuilt to match the engine there are other alternatives, the flipped Passat box, the SubaruGears and UN1 options
None of them are cheap 
Try finding a good core T3/T25 5 speed box of any ratio to start with that is now the challenge, hence the popularity of the other options, I don't have any good cores in stock and won't now buy any boxes without stripping them first because I can't afford to pay out 100s of £ and a day of work stripping and cleaning and inspecting only to find that the box is stuffed or has major expensive to fix issues
Subaru engine works fine with stock petrol gearing though slight benefits can be had if the box does need rebuilding but my advice is always do the conversion first be happy with the conversion and if you want to change the gearing having driven with the original gearbox then do a thorough cost benefit analysis first.
Low revs do not necessarily mean lower fuel usage, the engine needs be driven in its happy place and the happy place will be different to a car because the van is heavier and has a lot more volume of air to displace.

 

[triumph2.5pi]

Thank you very much for the detailed and informative reply Aidan, that's quite some food for thought. I've seen your website so may well be in touch