Five to Watch: Coca-Cola 600

The Monster Energy NASCAR Cup Series will reach the halfway point of the regular season after Sunday's Coca-Cola 600, the longest event on the 36-race schedule. With the culmination of a Memorial Day weekend packed with motorsports prestige, here are five story lines to watch for Sunday's 600-miler (6 p.m. ET, FOX, PRN, SiriusXM NASCAR Radio).

MARATHON, NOT A SPRINT: The Coca-Cola 600 remains flush with stock-car racing tradition, including the military pageantry, the placement on the schedule and the length, which has stood at 600 miles since the first running in 1960. The evolution of race car reliability has made attrition less of a factor, but the event still pushes drivers for extra distance. The advice from Kyle Larson, last weekend's All-Star winner: "Hydrate and don't ask what lap you're on."

ROWDY FOR A REPEAT?: Kyle Busch enters the 600 with momentum as a three-time winner this season, but he also has recent history on his side as the defending race winner. His long-run speed showed in Saturday's final practice, where he topped the consecutive 10-lap, 15-lap and 20-lap speed averages -- all signs that his bid for a repeat holds promise. "That would certainly be the goal and all of our aspirations here for this weekend," said Busch, who will start third in the 40-car field.

YOUNG SPEED: William Byron, 21, will lead the field to Sunday's green flag after becoming the youngest Coca-Cola 600 pole winner in Thursday qualifying. Byron was asked to rank his chances at a breakthrough Cup Series win, given the gains his Hendrick Motorsports team has made performance-wise. The second-year driver opted not to get too far ahead of himself. "I think you take it one step at a time," he said. "There are a lot of things we've got to do right to get to that point. But, I think the speed has been really good and the execution of our race last weekend was nearly flawless from a team's perspective and then from my perspective. So, I think we're getting there, for sure. We're close."

RAPID DAYS FROM RCR: Both Richard Childress Racing drivers -- Austin Dillon and teammate Daniel Hemric -- placed their Chevrolets in the top levels of the single-lap and long-run speed chart in practice. So far, their pre-race performance hasn't netted the same results this year, with only three top-10 finishes between the two. "I'm positive about the speed that we've brought from RCR this year. We need to just learn how to finish races better," said Dillon, the 2017 winner of the 600 who will start fourth Sunday. "It's so funny. Sometimes when you don't have the speed, you finish races good; when you do have the speed, it's harder to finish races. I don't know why that is, but we've got to make sure we capitalize on everything we can because we do have some speed this year, and I feel like we can make more noise the longer we go in the season."

DRIVING DOUBLE: The Sunday of Memorial Day weekend is a banner day full of motorsports clout, from Formula 1's Monaco Grand Prix to the Indianapolis 500 crown-jewel race for IndyCar to the Coca-Cola 600 as the day's NASCAR nightcap. Kurt Busch was the last to run both the Indy 500 and Coke 600 in the same day, in 2014. With the spotlight shining brightly on all forms of auto racing, more talk has emerged about the potential for NASCAR and IndyCar to share a venue in a future doubleheader. Denny Hamlin says he's all for the possible cooperation. "I think it'd be great. I mean I think that sometimes our fans are not the same and so it would be an opportunity to introduce each other," Hamlin said after final practice. "I've never been to an IndyCar race before, so it would be an opportunity for me to kind of see it up close and personal and I wouldn't mind wandering around the garages and seeing how they do things."