If you want grain, you will have better luck to overexpose a "regular" film, not to underexpose/overdevelop a T-grained film. Try HP5 or Tri-X at 100. Long development times via high dilution will give you more grain (and sharper grain) as well, and also help keep the contrast down to more easily printable levels, as opposed to strong dilutions, which will block up your overexposed film like nobody's business and will give you less grain (and softer grain).
Using Dektol is a common trick to kick your film in the teeth a bit. I find that D-19 kicks even harder, though. Nonetheless, you probably already have Dektol on hand, while D-19 proves a bit more difficult to locate these days. So I would try a starting test at 1:9 from the stock solution for 8 minutes at 75F, and go from there. This is with Arrowhead distilled water. If you are using your own tap water supply, your times could be radically different from mine.
Delta super speed film will give a grain "wash" as opposed to gnarly sharp clumpy grain. Yet again, overexposure will increase the grain.
If your film is too thick to print through after all this craziness, apply Farmer's Reducer as needed. Don't forget to refix and rewash afterward.