Do you absolutely HAVE to handpick exact length pushrods, when changing the heads, or is that associated with rocker arms? Or are the pushrods selected when doing both rockers and a head swap?
If that question doesn't make any sense, then please edumacate me.
if you dont mill the heads then you dont change the geometry and if you use the stock rockers then the stock pushrods will work, BUT I dont know of anyone who has ever put a set of heads on that didnt go with roller rockers(I am sure someone has but why).
Heads and rockers are like peas and carrots, they just go together. If you are getting some heads done it is a "good" idea to send your rocker stand as well as a rocker to your head guy so he can make sure the geometry is right and mill the stands if necessary and then you will need to check pushrod length and get new ones to make sure the rocker adjustment is within the acceptable range so oilflow is not compromised as well as PTV clearance.
John