eagle heads will take a longer pushrod because the valve length is longer. i was told you gain PtoV clearance with eagle head swap, this does not appear to be true as i measured valve to deck on 6.1 head and eagle head. you can get a 2"installed height with the eagle heads or better yet, change valves and drop retainer away from rocker to run a dual spring and your rocker geometry should stay pretty close

5.7 and 6.1 pushrods are 6.625 and 7.875

if using eagle heads, the pushrods are longer 6.81 and 8.09