Triumph TR4A Gearbox Tunnel - by Racetorations
This bit of kit is genius and so simple. A split gearbox tunnel with inspection hatches for the speedo angle drive and the prop-shaft grease nipple. It takes about 3 hours to fit if you are on your own. Keep your old tunnel as you can use it as a guide for the bolt holes as you will have to drill them.
Also, it makes sense to buy the Racetorations Fixing Kit too. I once had to replace the angle drive and without the inspection hatch it is a nightmare job. You have to strip out the drivers seat, lift all the carpet up etc. Takes a lot longer than the 3 hours to fit this tunnel.
I think money and time is well spent!