No it isn't the pushrods. It's not like this is the first setup that they've done. It's just that the stock lifters can't open and close fast enough for the amount of rpm this cam goes to. I'm going to get a set of Morels's and that will be the end of that.

 

Interesting... I'm running stock lifters with my V.3 cam.
I tried several pushrod sizes. 7.350" were the correct size

 

I also still have the LS1 intake, 853 castings, and no underdrive pulley as of yet.