Well as far as specs go I am not sure what they are but I do know that the engine is awsome. Rick Vessel was running a box stock and was as fast as 95% of the other engines. My engine had some crank work done on it and I was never passed on the straight and had more infield grunt than the track could handle. The most impressive thing to me was that putting the modified crank in did not change the way the engine wanted to idle . The engine was perfect, it would run for 8 minutes at 214 degrees. The outside temp was 90-100 degrees . Also remember that specs don't really mean much unless compairing them with the same manufactuer. My crank had some work but look at it like this, 159.00 for the engine (120.00 less than an x12) , so once you have it modified (100.00) , it is still cheaper , just as fast if not faster , and has the best carberator on the market(reliability). If anyone would like work on their engines , let me know and my guy will do them for 100.00. you can contact me at [email protected].