NPR Piston Ring Set - STD.

Worked great in my F22A6. It's a 24 Hours of Lemons CB7 race car and I have 1 race on them so far, they're holding up great. I just did a quick ring job with the block in the car and a dingleball cylinder hone. Stock 250k mile pistons.Broke them in hard immediately after getting the motor back together. 10 full throttle runs from 30-60mph in 3rd letting the car engine brake back down to 30 each time with the throttle closed.