As Dazs 4x4 said
These are good - made by "GATES"......some peeps sell them as "Group A" items at a premium price
.....but if you shop around (motor factors) they are not too expensive at all
Also available on-line from here:
I quote:
"O.E. Timing Belts for Cosworth Engines - Says it All!"
http://www.motorsportsuperstore.com/...asp?pc=GATESPG