yep, on how deep the pushrods were into the lifters with the stock set up ie if they were already .150" down then ya pushing it and depending on the base circle of the cam you intend to use

Use adjustables then you know exactly how much preload you are putting on the lifter

Tightened properly with a drop of blue loctite you'll be fine

get the S&S quickies, I don't use loctite as it can some times take a while to get them set in the right position. never had the nut come loose, no need to put a heap of tension on them either just enough is good to go.
There is a reason a 7/16' spanner is short

who,s up set hd owner hes done a runner again ?