Can you buy and use a inner spring that will give you between .015 to .040 or so clearances cold to the bottom lower inner small step on your valve guides?
If so do that
![twocents twocents](/ubbthreads/images/graemlins/custom/twocents.gif)
I have used those specs on a lot of iron headed motors, both drag race and street and strip with no issues at all
![up up](/ubbthreads/images/graemlins/custom/thumbs_up.gif)
Iron heads don't really need spring cups or locator unless you want them.
I do use either a spring cups or spring locators on all my aluminum heads also though
![up up](/ubbthreads/images/graemlins/custom/thumbs_up.gif)
EDITED: You can buy a spring seat and valve guide cutter tool to reduce that lower inner step also
![scope scope](/ubbthreads/images/graemlins/custom/scope.gif)
I've had to do that more than once to get the clearances I want down there
![scope scope](/ubbthreads/images/graemlins/custom/scope.gif)
Isky and Comp Cams both sell them
![scope scope](/ubbthreads/images/graemlins/custom/scope.gif)