I have had perfect results in using cut and coated pistons in a DD, puller and racer motors. Tuning is 95% of piston failure. Using the right tunning and engine builder makes all the differance in the world.
In the four years i have been selling these kits we have had only one broken shaft and it was caused by ring and pinion failure. So there is no written warranty but if you were to break one we can send it in for failure analises and if it was a manufacture flaw they will make it right. I have...