516 head question

Yeah that was a 516. It would be a good idea to buy an install height mic. If you have calipers you can install a valve with a retainer and keeper's together. Just pull up so the valve is seated and measure from the spring seat to the bottom of the retainer, that will get you really close.
It's very easy to do and you can set up your own heads
If you need to take a spring to a shop and have it measured, I guarantee they won't charge much.
true thats a handy tool. I am getting a shop to build the heads. I just wanted to gather up as much as I could and use something more severe duty wise than sbi replacement suff. I hope I'm making the right choice because its been a merry go round to get this done. I dont know how I pulled it off back 35 years ago in a hay barn