'65 289 rocker arm geometry help

[F-ONE]

As said those are the wrong valves for that head.

That's OK as you can simply get rail rockers, mid '66 to '77 or so. Those valves have to have rail rockers as darrell said.

I will add that you have to have hardened pushrods as the small hole early heads guide the push rod.

It' really a good set up as a performance upgrade for rail rocker heads was guide plates. Early heads do not need guide plates. Just make sure you use hardened pushrods.