All top Ford drivers to have latest engine at Pocono Sunday will be a red-letter day for Ford's new FR9 engine, with Greg Biffle, Matt Kenseth, Carl Edwards and AJ Allmendinger all set to run it in this weekend's Pocono 500.
The engine, which has been used only occasionally since it was first rolled out almost 18 months ago, has been something of a mystery, apparently even to most of the Ford drivers.
This month has been targeted since January by Ford racing boss Jamie Allison as the point for the full rollout of the new motor, which is not only a new design but with all new parts throughout.
Ford teams have been struggling this spring, and now drivers will see if the new engine can change that dynamic.
However it probably won't be any panacea, because Ford's current engine has been one of the best in the sport, and drivers have complained more about how their don't seem to handle as well as rivals'.
The new engine was designed in part to run cooler and more efficiently, which should allow teams better nose-aerodynamics, which in turn should make the cars turn better.
That, rather than simply more horsepower.
Biffle says at Michigan next weekend all nine Ford teams will be using the FR9, "but it will hop-scotch after that due to parts supply and how things go.
"When you are trying to build engines for nine teams, that is 18 engines a week. It takes awhile to ramp up and handle that amount of pistons and rings and all the other parts.
"That is a lot of pieces to have on the shelf...and you don't want to go out and buy all that stuff until you know you have the right part.
"It is kind of a double-edged sword: You can't go buy the stuff until you know what you need. When you know what you need, you have to guy buy it, but they have to make it.
"It takes a long time to integrate all new stuff.
"It is a lot of pressure on the engine shop, though. They still have to build the old engines, and now they have to build the new engines. They are having a tough time, but they are working very hard."