Does any one know this? I need to know the size of the head of the bolt not thread size. And these are Pacesetter LT1 Header Bolts, and Breslin 10 Point Header Bolts for LT1's. I just need to know because I dont have any tools here at home and was gonna ask my buddy who is a mechanic to bring some home with him. Thanks

 

Breslin have a 3/8 12 point head.

 

Thanks, Now I just need the pacesetter sizes.