using common tools as a guide. QUOTE]
Guys,
RRR hit it on the head (no pun intended) when he used the word "Guide". The socket and screwdriver are there for you to measure progress (it does get exciting), and as a reference from one port to the other. I almost always have to go back and touch up a port or two when I think I'm done. This is where the reference is important. I've even used a small socket and passed it through the ports instead of the screwdriver. But the screwdriver helps with "straight through design" on the exhaust (and exhaust only), plus the handle works to size the port as well.