Tri-X processed in PERCEPTOL at a normal contrast will give a film speed of around 250-320. In order to get a film speed of 400, you will need to develop the film to a higher than normal contrast. It will give you nice fine-grained results, but you will probably end up printing the negs about one half to on grade lower than normal.(posted 8194 days ago)Since you shot the film at 400, I would suggest sticking with a normal developer, such as ILFORD ID-11 or Kodak's D-76.
For the film shot at 800, MICROPHEN would be an excellent choice of developer.
Of course, next time try ILFORD HP5+ instead of the Tri-X. ;-)
David Carper ILFORD Technical Service