stop being a fuckhead and send the athena to redline, your gunna end up with junkass ported stockers and still nowhere closer to getting a running bike....ebay the Trex and sink the money into the athena....get pistons from redline and send them head your gunna use too.
specify the gas your going to use (octane rating), your elevation (sea level), carb type and size...and get jetting recomendations, coz you`ll "blow" pistons all fuckin` day if you dont get close to having a clue (write it all down)
you`ll end up with less than what you got now and money down the drain
these badass stock cylinder set ups that caught your eye are alky bikes, NOT suitable for trails, the athenas will be fine once redline has sorted them out
you race a ltz400 for MX...do you beat ANYONE on that thing? < ignore that question and focus on that^