is thermostat housing bolt metric?

[gem6.9]

hello, i twisted the head right off the block side bolt on the thermostat housing, i thought would be a fast job to change the stat. anyways, is this bolt metric and is this a ford bolt only, thanks for any help.

 

[typ4]

No, it is standard and it is just a grade 8 regular bolt 5/16 course

 

[gem6.9]

lift pump bolts

thanks a bunch, i will be getting one after work and finish the job, the new ford stat works real good in a boiling pan of water, the old stat is real sticky, i cant wait to try it out towing, thanks agin.

 

[RLDSL]

A lot of those fasteners make you wonder. Most of the 1/2" head ones , a 13mm socket fits better.