whats up with the double ringed pistons people are putting in the twin 7's are they 670ho pistons or standard 670's please help.

You can use the HO/X flat tops or the regular 670 domed. Depends on the head you are using and if you shim the base or run stock gaskets. Lots of different combinations are possible and have their pro's and cons. There are also some non doo L ring pistons that work well (what I'm using). If your 7 is due for pistons I'd highly recommend using them.