That's been my experience, too. I have replaced as
many as 8 7474s
at a go to get an -8/L back on its feet. I don't recall replacing
any other chip, as a matter of fact.
-ethan
Remember earlier this winter when I was restoring my 8/L, I had one or two
bad 7474's but EVERY 7440 with date code 7005 was bad!
-Charles
ps still looking for someone to help with my ASR33 tape reader error rate,
so I can finish revising my DF32x4 NVRAM project.