TR4 Engine + 2000 Saloon Gearbox ?

[Electron]

I have a fibreglass special that I'm using TR4 running gear in.

I have the back axle engine and front suspension but need to find a gearbox.

Non overdrive TR4 boxes appear to be rare so I am looking further afield. I understand I can use a 2000 saloon J type box but need a different clutch plate ??

Can anyone clarify before I purchase one ??

[Electron]

Getting there ...

The input shaft on TR 4A/5/6 gearboxes is 10 spline x 1.25”.

The input shaft on 2000 Saloons and Sprints gearboxes is 10 spline x 1.00.

Later gearboxes are longer so need new mounts.

Apparently Moss will do a clutch .....