Ok here goes with what i have found.The brake pads i have ended up useing are from a 1975 xj12 5.3 they are the same as used on the Godspeed 335 kits after lots of searching on google.They are on the left motoquip number vxl337
Dimensions (mm) 120.0 x 70.0 x 15.6 standard is vxl610
Dimensions (mm) 120.0 x 70.0 x 14.0.
The Jag pad fits great but you can not use the standard shims as the pad is 1.6 mm thicker.You also have to lenghten the pin holes by a few mm.
Here they are fitted
Did a 100 mile trip last night and got to say the brakes are now spot on with lots of feel very pleased.This is where the disc's come from off ebay the guys were very helpfull.
http://cgi.ebay.co.uk/Impreza-P1-Dri...mZ290307123735