You DID say any advice is more than welcome. I'm going to get another chewing out for saying too much, but if you chose 35mm Tri-X and Rodinal as your staple, you couldn't have picked a grainier combo. Not a lot you can do but go with the standard dilution and learn to love grain. With that, you'll get the contrast, if you're willing to pay the price. But then if you plan to do photography only a couple time a year or decade, the Rodinal will be there without having to buy more of the other developers every year or 2 when they go rancid.