Blaney, who won last weekend’s race at Atlanta Motor Speedway, posted his session-leading fastest average lap speed (89.232 mph) early in the 50-minute practice.
“It was rough, slick. Really rough, actually,” Blaney said of Bristol . “The track is kind of coming up and there are crazy big divots. It’s definitely not smooth.
“You just run through things that you think will work. There wasn’t really much lane-changing going on. (Kyle) Larson and (Tyler) Reddick could run the top for a while and then that kind of went away after a handful of minutes.
“We’re just trying to keep tires on it. We’re seeing a lot of tires cording pretty quickly, especially right-rears. Right-fronts started to go pretty quick, too. That’s something that’s going to come into play is saving your tires.”
Bowman’s fast lap (89.135 mph) came in the session’s final minutes. Bowman also had the fastest average lap speed in Friday’s first practice. Denny Hamlin ended up third-fastest (88.985 mph).
The practice was marred by a lot of dust from the dirt surface and several times during the session, various drivers complained about problems seeing out of their windshields.
“At the moment, it’s pretty dusty. Everything that is not black right now is pretty dusty,” Bowman said. “They’re in a tough spot with all the rain coming in and doing the best they can.
“I had a blast. I still thought it was a lot of fun.”
Joey Logano and Chase Briscoe rounded out the top-five.
Completing the top-10 single-lap speeds were Martin Truex Jr., Chase Elliott, Michael McDowell, William Byron and Kyle Busch.
Midway through the practice, Larson reported that the water temperature had spiked in his No. 5 Hendrick Motorsports Chevrolet.
Eventually the team decided to change engines, which means Larson will have to start Sunday’s race from the rear of the field regardless of where he finishes in Saturday’s heat races.
Among the drivers who ran at least 10 consecutive laps, Larson had the fastest average lap speed. He was followed by Hamlin, Tyler Reddick, Elliott and Bowman.
There were only a couple of on track incidents, with one involving Kurt Busch tagging the wall with his No. 1 Chevrolet.
With just under five minutes remaining in the session, Cole Custer spun off Turn 4 to bring out a quickie caution but he didn’t appear to suffer any damage to his No. 41 Ford.