I've seen a few now for around the 1-2k mark now

I know my gearbox is in really bad shape. The zf tune hid it for a while but now with the standard one in its just woeful.

I have seen second hand built ones for 4k but who knows how good they are

I went to the pwr about 12 months ago circa ~85-90,000kms, I did it for peace of mind. One day hoping to also run an oil to air cooler in series with the pwr, thermostatically controlled to keep zf temps down on the track.

Built ZF's are getting cheaper. Gilroys in QLD doing them for 3k with cryo shaft. Plenty running them with no issues.

I've seen a few now for around the 1-2k mark now

I know my gearbox is in really bad shape.

1K if you are lucky.

But if your box is on its way, yeah, you could probably halve that price.

Can run a 10 with manual, dont be a girl

^^^ Thread pirates!!!

But wtf , Matty I think you'll come close to spending 6k on a conversion..... Yeah?

May as well buy a box as a spare & slowly build it up yourself. There's a quite detailed teardown that can be found on a jag/range rover site. Pretty simple box to pull down and one could imagine to build up

I'll be spending close to 5 on a conversion

And that's the same with a built box

Choices

I've looked into building it myself but I am not confident enough in my abilities to do that

I still have the original heat exchanger on my F6X. Car has done over 90k km's but I have been wanting to change it over to just an air cooler from either PWR or a B&M Supercooler like I did with my BA!

I'll be spending close to 5 on a conversion

And that's the same with a built box

Choices

I've looked into building it myself but I am not confident enough in my abilities to do that

What's there to know? Everyone will need to forgive my ignorance but one of the main benefits of the 6hp series boxes is that they are built with no need for fine shimming & adjustment. All parts are just machined to tol and assembled to torque, eg semi skilled labour is required to produce them. Is there a finer point to building a box I am neglecting?

Initial thoughts would be to install slightly thinner, but more clutch plates to assist in building the friction, input shaft etc. Next stage would be swapping all the gears themselves for more robust materials as a 'stage 2'