IN THE ARTICAL ON HOPPING UP YOUR LT1 OR 2 BY INSTALLING CAM NEW VALVE SPRINGS AND ROLLER ROCKER ARMS AND A CHIP FOR 175 RWHP THE PIC ON THE VALVE SPRING INSTALL LOOKS LIKE THE DID NOT REMOVE THE HEAD TO INSTALL THE VALVE SPRINGS MY ONLY GUESS IS THAT THE PUT AIR IN THE CYCLINDERS TO KEEP THE VALVE FROM DROPING BUT HOW DID THEY COMPRESS THE VALVE SPRING ? DID THEY USE A SPECIAL TOOL ? NEW TO THE FORUM SO IF THIS HAS ALREADY BEEN AWNSERED JUST LET ME KNOW WERE TO LOOK TO FIND THE AWNSER THANKS  

With heads still installed, best way to change the springs is to use a special fitting and fill the cylinders with air. Another old trick is to fill the cylinder with small diameter rope to keep the valve from dropping. But i'd stick with compressed air.

As for compressing the springs, Crane Cams has the best valve spring compressor out there for either LT1s or LS motors, especially if you've got a 4th Gen F-body.  

thanks i'll check it out