these are engine blocks created for honda motors and acura motors they were made for racing on the track/street and they are made so that it can withhold the pressure of boost in the engine they are also known as “dark blocks” they have made them for high amounts of turbo boost or and high shots of nitrious.
i got a (Dart) block that is maid for honda from Jegs racing its a very nice block
It’s DART! Not DARK! Even Paul Walker would have know that!
Try Summitt racing.