Trim any fat from the steaks and place in a large ziploc bag.
For the marinade combine lime juice, oil, chili powder, garlic and salt. Pour over meat and seal. Let marinade for at least 4 hours in the refreigerator.
Preheat grill and grill steaks over medium to medium high heat until desired doneness. I cooked ours about 4 minutes total. This will vary greatly depending on the cut and thickness and how well done you want your steak.
Remove from grill and let rest for a couple of minutes.
Slice into 1/2" wide strips.
Fill tortilla with meat, avocado and pico de gallo.
Makes about 12 tacos