is it really 100% nessecary to run a longer valve with a solid roller setup, if so why and what length is required? thanks in advance.

 

Depends on what spring pressure you want to run, what springs will fit, and what installed height you need to use.

I for example ran .100 longer Manley SD valves in my 6.0 heads to get it all right.

My new heads won't have longer valves I don't think.

 

You could also run lash caps. I love them, they also provide a larger contact patch to work with. You can get custom sizes as well. Some people dont like them, I however, think they are great.