How much oak chips should I use?

a friend showed me a Denny Conn recipe on-line for a vanilla bourbon porter that sounds really good! In the recipe he uses 1-2 oz of oak cubes in the secondary... but I have oak chips, he recommends using less but doesn't say how much. It's for a 6 gal batch. I was going to soak the chips in the bourbon with the vanilla beans and then just dump the whole thing into secondary. I'm just not sure how much chips to use. I've never used them before.

As a general rule, use less chips than cubes to obtain the same level of oaky-ness (it's a surface area thing). 1-2oz should get you where you want to go flavor-wise, but this will take shorter to get there than cubes. A good practice is to check the flavor often after about 3 days of soaking. When the flavor is *just* too much more than you want it, pull the oak and package. I say "too much" because oak flavor will fade with time.