smog heads?

Can anyone tell me, if I fun ford 302efi smog heads, do I need to plug off the ports or can they be open?

 

Gotta plug em' I'm building one now and I need to figure out the best "cleanest" way to do it.

 

Just find a short bolt with the right threads, and use loc***e. It's back by the firewall, likely won't be seen.

 

Depending on the year... The ones with the big hole can be fitted with a freeze plug or a washer and bolt.

Other years have 5/8"-11 thread. You can use a 5/8-11 x 3/4 long bolt, or buy part F4ZZ-6E086-A from a Ford dealer.

 

Cool, thanks!