Cleaning my AFR 195 heads today and notice that they have a hole in the exhaust port the goes into the intake side of the head. I thought something was wrong andmaybe AFR made a mistake, so I go get the other head and see the same hole. Whta is the purpose of drilling a hole through the intakle side of the head to run into the exhaust port of the maniford. This will allow burned exhaust gases to get back into the maniford. I's this just some technology breakthrough that I don't know nothing about or what?
Look at this pic for the intake side and this hole runs into the exhaust portbehind the valve. Only one exhaust valve have this hole on both heads...
AFR 195 (http://f1.pg.photos.yahoo.com/ph/dtl5042002/detail?.dir=/5653&.dnm=5864.jpg)

That is the exhaust crossover for heating the intake on cold starts. It is used in conjunction with a heat riser valve on the right side exhaust. If you have headers or don't want to use it, use intake gaskets that block it off.