The problem with using a block off plate on the head is that hot exhaust gas gets trapped in that port and I guess it has caused the #6 cylinder to bite the dust for some people due to heat.
Im not sure if that's on boosted cars or in general.
At the very least if you delete your egr, you need to thread that hole on the head and screw a long bolt in there so exhaust gas doesnt have a place to build up and heat up that area.
If you arent planning to thread that port and stick a long bolt in it for good, dont bother with the block off plate, it could cause you a huge headache down the road. Also, people have reported a loss in miles per gallon from deleting the egr stuff.
Search google and you will see, there are a couple of old threads on supraforums regarding this.
Last edited by GSXMike; 04-28-14 at 12:45 AM.