My 15 yr old has started "working" on our '76 F150 farm truck. He found my old set of mustang shorty headers and he wants to install them on the 302. He's asked me to bring header bolts home but I am not sure of the threads - I'm pretty sure they'll be 3/4 long. Any help?

 

Think I am able to answer my own question. 3/8 coarse. Chime in if I'm wrong.

 

3/8-16 is thread size.

 

Thanks for the confirmation.