Does anyone know off the top of there head what the fastener size is for the inner fender wheel well? the black plastic pieces.

Makes it easier to get help. If we do not have to guess on what car you are working model and year makes a big difference here. Actually in some cases even the month matters. I also suggest you pick up the parts CD. Supports the club and also saves you time waiting for an answer.

Doh!!! my bad, It's a early '77.

10mm I think