depends on what you want them for ( street use, racing only ). as others have said, Formula Ford tyres. i used to have a set of F/F AVON racing tyres ( had formula ford on the side wall ) and they were awesome! from memory cost $200 and they came on a set of 13" custom or Formula Ford 12 slotters and looked like this:

wish i never got rid of them but they went with the car when it was sold!