Correct rad cap for 67 L36

[2qwik2c]

Hi, what is the correct rad cap for a 67 L36 427?? RC15??? Or maybe a RC32?? Please help. Thanks.

[firstgenaddict]

Big eared RC15 but there are 2 or 3 rivet designs... not sure which one a 67 takes.

[Pacecarjeff]

The 66 -68L used the RC 15, with the hollow brass rivet.
The top of the cap has 2 circles, one with AC, the other with RC15 in them.