Grate cheddar and pepper jack cheeses using a box grater. Set aside.
Beat cream cheese in a large bowl until smooth, about 1 minute. Add mayonnaise and mix until fully combined.
Add Worcestershire sauce, garlic powder, onion powder, cayenne, black pepper, and salt. Mix to incorporate.
Fold in grated cheeses and drained pimentos. Fold gently for a chunkier texture or mix more vigorously for a smoother spread.
Taste and adjust salt or cayenne as needed.
Cover and refrigerate at least 1 hour before serving.