For USDA Select, even though they are from the belly of the steer, they have some nice marbling. I agree with using low grilling temps and I cook mine raised direct, about 10" above the coals. This marinade has sugar, so be mindful of that when grilling, sugar can cause premature darkening or even burning if your coals are too hot. Here is my Bulgogi style marinade, which I also use on racks of domestic lamb:
Korean Bulgogi Style Marinade – Marinade times of 4 hours for thinner meats, and up to 24 hours for 1" thick steaks or chops.
1/3 to 1/2 cup soy sauce (I prefer 1/3 cup)
1/4 cup rice wine (or dry sherry)
1/4 cup water
4 Tbsp finely chopped green onion
1 Tbsp finely minced garlic (at least)
1 - 2 teaspoons finely grated fresh ginger (or ginger paste, or cracked ginger)
2 teaspoons crushed red pepper
1 Tbsp sugar
1 teaspoon dark (Asian) sesame seed oil
1/2 teaspoon fresh ground black pepper
2 Tbsp toasted, crushed sesame seeds (we have these in a jar or you can fresh toast them)
Mix the marinade and sample. If it is too strong, thin with water to taste.