There's nothing wrong with your reasoning. As long as you are aware of the advantages and disadvantages both ways, then the choice is yours.

That would be a great test and I was going to suggest doing that. However, maybe not just 1000 miles. You have your old tests. Run a few more...3000 miles, 6000 miles, 10000, etc, etc and see if notice any particular trend. Water is one, but maybe increased metal levels somewhere else if the moisture is causing corriosion, etc.

does that work better then a regular drill bit?

oh yeah, especially in thinner sheet metal. regular bits make triangular holes, unibits make round holes. harbor freight has a pack of 3 assorted sizes for $10 and they are decent quality.

Only problem I found with that was it leaves a stair stepped hole.... A Forstner bit or flat bit or auger style works good too.... Your right though Shawn those do rock, I use mine a ton!

so link me to the bit you guys recommend lol. i havent bought the drill bit yet, just the tap so far. i have to use a smaller bit anyways to drill a hole lower and then connect it with the original since the hole sits so high on the valve cover. but link me to the bit that will make the final 5/8 hole the easiest

If you want a clean hole then this is the type I recommend. If your going through thin metal then all in one posted will work.

http://upload.wikimedia.org/wikipedi..._Bohrer_01.jpg

here are the bits i use, but for what you plan on doing you are probably going to need to do it with a strait bit and a board clamped to it.

http://www.harborfreight.com/3-piece...lls-91616.html

Mine did a 3/4" hole without the step on my VII VC. The steps are wider on mine than in the picture. Worked better than I thought. They sell them at Harbor Freight. I used JB Weld to glue the -10AN bung but now I wish I would of tapped it and used a threaded bung.

Another way to tell if you're venting enough is to hook up a cheap boost/vacuum gauge to the VC one of the vent tubes and make sure you're not building pressure inside.

Your going 5/8 (npt)???

Those are my bits.

http://www.harborfreight.com/media/c...image_2386.jpg
I used the one in the middle which explains why I did not stair step mine when doing a 3/4" hole.

I did not clamp mine down. The magnesium is like drilling through alum and it felt fine just holding it with one hand and drilling with the other. Clamp is always safer though.

Yeah I hear you.... The reason why I mentioned that is because I did a 3/8 npt. So I had to have it deep enough to tap it properly.

my bad its 1/2 NPT lol. 5/8 would be insane

I was gonna say.... I was thinking you wouldn't have room... :lol:

are you guys chiseling the baffles out then gluing them back in place or what?