If I am replacing my 1.450" valve springs and putting in 1.415 beehives, do i also need to change the seats the original springs sat on, or can I use them? Also, it says inner springs are not included, do beehives use inner springs?

 

The outside diameter of the seat should correspond to the O.D. of the spring or be within a very few thousandths of that. Slightly larger is better than slightly smaller.

 

Beehives don't use inner springs, which is the whole point. They are a single spring design.

You should buy the correct locators/seats for the beehives.