Although I don't know how you are developing your films, I can at least
tell you what my tests have revealed. I use T-Max 400 4x5 film and develop
it in BTZS-type tubes. They are just six inches of ABS 2" tubing with a couple
of end-caps. I use 3.5 ounces of developer in each tube. Using this method,
I have found that a delta-log H of about 2.0 can be obtained with HC-110
dilution A for around 8 minutes at 68 degrees. Again, these numbers will
probably not hold true for other types of development or different films
(testing your own would be a good idea), but this may be a reasonable
approximation to start with. Good luck.
Adam.