Martin Truex Jr. competing in Daytona 500 in No. 56 his late father drove

When Martin Truex Jr. started discussing a deal to compete in the Daytona 500, he had a unique request: Could he drive the No. 56?

It was a resounding yes from Tricon Garage, and the decision has become even more special for Truex in the weeks since.

A day after Truex formally announced his entry into "The Great American Race," his father died unexpectedly at age 66. Truex Sr. drove the No. 56 for much of his racing career, which included 15 starts in the second-tier Xfinity Series and 135 starts in the ARCA Series in the 1990s.

"It probably means more. It probably hits home more with me of just what it means to us and our family," said Truex Jr., who drove the No. 56 for four seasons (2010-13) at Michael Waltrip Racing. "A lot of people are going to be excited to see it out there."

[Read more: Who are the 10 greatest Daytona 500 drivers of all time? ]

It might be most emotional for the Truex family, specifically Martin and younger brother Ryan.

"Everything I've ever learned was from him," Martin said. "He was my hero growing up and still is. He made a lot of things happen for me. Taught me a lot of things with racing and really the opportunity to get here and what I've accomplished is all because of him and his sacrifices. Hopefully, we'll go win this thing for him on Sunday."

It would be the ultimate tribute. And no one should count Truex out even though he's winless in 39 starts at Daytona International Speedway. Truex has the longest active losing streak in the Daytona 500, having failed to win in 20 starts.

But he came close in 2016, coming up inches short of Denny Hamlin in the closest finish in the history of "The Great American Race."

Truex hasn't been nearly as close since, although he has finished in