Hydraulic Flat Tappet lifter question / Desoto Firedome

I have less than 100 miles on a fresh rebuild of a Desoto 330 Hemi. The lifters sounded a little loose so I re-torqued the heads and readjusted the lifters. Everything sounded good. The next day I started it up and now I have a different lifter tapping very loud (no. 1 exhaust) on the opposite bank. I pushed on the pushrod and could feel the spring in the lifter collapsing. After doing this a couple times, I started the engine and everything is quit. I did notice that the pushrods on that no. 1 exhaust was not rotating along with 2 other pushrods not rotating while the engine is running. So my questions are; do I have Bad lifters? Is there an oiling problem that is preventing the lifter from pumping up?
Thanks in advance

 

Do yo know what your oil pressure is?

 

Hello Bill

Just fired this thing up this morning and all lifters are quiet, however 3 pushrods are not rotating which has me concerned. I am putting out about 75 lbs. oil preasure @ 150 degrees engine temp.

 

I pulled the top end apart today and removed the lifters. There does not appear to be any abnormal wear pattern to the lifters. The cam has the same wear pattern on all lobes

 

A bit of relief
I put the lifters back in the holes this morning with a mark. I did the same with the push rods. All The lifters are rotating properly but the 3 pushrods are still not rotating. I swapped the pushrods and they will turn on a different rocker.