Rocker Pedestal Cracking?

I am working on putting a 2000 5.0 exploreer engine in my mustang. My mustang engine came with 1.72 roller rockers but i do not know what brand they are.
i put cylinder 1 to tdc and installed the two rockers just fine. i moved on to cylinder 3 and the intake rocker went on fine but i have cracked 2 pedestals when trying to put the exhaust rocker on.
What could be causing this? I torqing them down to 20 lbs and i am not even hitting that before they crack.
i am pretty sure i have the cylinder at tdc on the compression stroke. basically, when cylinder 1 wase on 0 on the harmonic balancer dial marker, i turned it 1/4 of a turn for cylinder 3. both of the pushrods seems to be at their lowest point.
the process i am using to tighten the rocker stud is, hand tighten it until i cant hand tighten it anymore(i use a hex socket to hand tighten since i can fit my fingers in the rockers slot) then i start to torque it down making sure i don't go farther then one revolution. the pedestal will crack at about a half turn.

any help and advice will be greatly apreciated. I ordered some, studs, pedestals and shims from summit.

thanks,

ok, i think i figured it out. There is a flat side and rounded side on the fulcrum that the bolt goes through on the rocker arm and the bolt head needs to be resting on the flat side. The pedestals i cracked had the bolt head on the rounded side.

So, now i have 3 exhaust rocker arms that can not go on, cylinder 3, 7, and 2. Can i continue to install the rest making sure i follow the firing order and tdc on the compression stroke? Then i will in stall the remaining once i get my extra pedestals. Of course, with the remaining i will following the firing order again making sure it is on tdc.

Will this work?

Thanks,