Mk3 Cavalier Owners Club | Vauxhall Cavalier Dot Com

I want to upgrade clutch to a hydraulic set up

I cannot see this as being too dificult as long as you have a good sound practical / mechanical background.
Not something for a novice.
A lot of later cars (Astra-G, Vectra-B) used the same gear boxes such as the F18, but with hydraulic clutches.
Just a matter of getting all the necessary parts and fitting them to your car.
Perhaps a bit of head scratching to identify how and where to locate the necessary conversion parts.

Why do you want to go hydraulic?
If it is because of a heavy pedal, then it could easily be a tired diaphragm or a faulty cable.

My cable was severely damaged during a recent restoration.
When it finally gave up, I fitted a new one, and was amazed at how light the clutch became.

It would be a box off job anyway to fit the slave cylinder and the release bearing actuator / link rod mechanism.
Then there is all the routing and plumbing in of the hydraulic lines to the clutch master cylinder and the pedal assembly.

So it may be simpler to fit a new clutch kit, release bearing and perhaps a new cable.

The box I've got to suit my 3.2 v6 conversion is hydrolic clutch hence the change way would I need to make it work

3.2 v6 gearbox.

I presume that is a Vectra-C engine from a pre-facelift GSi.

I cannot say whether that box or engine would have the correct location points to fit the Cavalier / Vectra-A engine bay.

Sounds like a lot of conversion work will be required.
There is very little that cannot be done with the correct modifications, plenty of money and a very large amount of technical knowledge.

I would get the clutch pedal box assembly, all the pipe-work and the master cylinder from a Vectra-B or Astra-G as they may be the easiest to adapt to fit a Cav / Vec-A.

The slave cylinder and associated plumbing should already be in situ on your planned gearbox.
So a matter of joining the master cylinder pipe-work to the gearbox pipe-work.

It will take a lot of trial fitting to find the best fit, and will probably need some cutting, drilling and welding to get the pedal parts and master cylinder to fit, and to get the engine / gearbox mounts to line up and fit.

You will also need a custom exhaust to get the 3.2 v6 to run and fit properly.

what box are you planning on using? As Robsey said, lots of factors to consider.