-the best method is to use a race pipe with the EGR delete: this removes both the EGR valve and the EGR cooler completely
-the next best method would be the block plates: that will completely block the flow of the exhaust gas.
-last would be the paper clip method: this disables the EGR valve and prevents flow into the intake. is it 100% sealed ?? i would think at lest 95%
if you install a race pipe you will need to leave the EGR attached.. this is what i did for a buddy to remove the entire valve.. i have a big band saw at work and i gave it a chop! now he just has the motor off to the side and not look ghetto.
