Kodak's publication F-9 (the datasheet for Tri-X and Tri-X Pro) recommends for a three stop push that you use Tmax-RS as your developer. D76, HC110 and Tmax developers are listed as not recommended for a three stop push. Development is recommended for 11 1/2 minutes at 70 deg F in Tmax-RS.(posted 9176 days ago)One note, the contrast is going to go way up and you can expect to pretty much lose any shadow detail in your image. Depending on your subject that may or may not work against you.
Good luck.