how to install egr valve
 

i have a 302 carb'd, with no egr valve. i am sure its one thing thats holding me back for e test. my intake is a performer air gap, with 600 performer carb. at the back of the heads it looks like there were some kind of tubes that are cut and pinched.i think the block and heads were from an 87. anyone know what i need to do?thanks