340 cracked pushrods

Guys this is a .429/.444 cam.Actually lighter than the 340 4-barrel cars came with.
Is the Chain set in at Straight up?
Did you BLEED the Lifters when installing?
Did you make sure you had all the push rods seated in the lifters correctly?
Anything cut off of your heads?Block?
What Piston did you use?

I have had Rockers Split out WELL before any Push Rods..

SS