Hi all,
I think it should be relatively simple and not too expensive to convert a TR g'box to use a hydraulic clutch release. Yes, the British vendors are offering TR-specific kits, which would probably be the easiest fit, but probably are based upon US-sourced Tilton universal releases that you'd be re-importing at additional cost. When looking at TR vendor sites in the UK, they usually include 17.5% VAT, which you won't have to pay. On the other hand, shipping from the UK is pricey.
There are four or five US manufacturers of these releases. I don't know what's used on the Toyota 5-speed, maybe it is a possibility too.
I've been researching a little and Tilton seems about the most popular/reliable universal model that's possible to fit to TRs. There are two Tilton universal, not sure which one is right for TRs, that sell for $271 and $296 at Summit Racing. (
https://store.summitracing.com/default.asp?target=egnsearch.asp&N=400017+314983&autoview=sku ) An adapter plate would need to be machined to mount this to the gearbox. Shimmmed to fit, plumbed and it's done. Pretty simple and should give quicker shifts as well.
I figure the cost of a stock TR setup done right - new T.O. bearing, new bearing carrier, new greasable cross shaft (TR4 & earlier style), new release fork, new dreaded taper pin, new shaft bushings, new slave cylinder - would all add up to about the same, maybe a little less. If upgrading to a Gunst T.O., it would likely cost more for TR4A/later, and a lot more for TR4/ealier where it would also be necessary to replace or modify the flywheel and change to the later style clutch and pressure plate (if those aren't being replaced anyway).
No, I haven't installed a hydraulic release on my TR4. Everything in it is new. But, at the slightest hint of trouble, I'll likely give the Tilton a try.
I don't see the 5-speed conversion as necessarily devaluing a car. It's a reversible modification. Just hang onto the TR gearbox and, if a sale ever happens, it would be possible to reinstall it if the new owner wishes.