It's just like everything in a motor there is always ways to make some things better, I definitely do the most critical first then the less critical last if I have the $, If you don't have push rods yet raise the shafts and see if you can make it better, If you already have push rods I would just leave it there it will work fine. A engine can be a never ending money sucking vacuum if you let it, or you can make a good engine that serves your purpose for reasonably cheap. Or anything in between.
