I'm getting ready to fix a leaking ip gear housing on my truck (where the housing meets the block, on the driver side, right above the water pump). I've seen posts of a few ways to do it and not disturb timing. Just wanted to know the BEST way to get this taken care of from someone who has done it with success. Thanks in advance!

 

Yup; that happens. You need new silicone/RTV, a wire brush and other instruments to get the old RTV off, and plenty of patience.

What I recommend is that you pull the end-cap off the IP cover(two bolts, front of it), so you can see inside. Rotate the engine until the dowel pin is upwards.
Unhook the battery, put it in neutral, whatever it takes to make sure you don't accidentally rotate the motor.
Unscrew all of the 8 injector lines at the injectors. Disconnect the fuel-filter-to-IP supply line.
Now, just unbolt the whole thing, turn it upside down and clean it. Clean the mating surface as well.
When you put it on, you just need to make sure that that dowel is straight up, and you'll be on the correct tooth.
Put it all back together, bolt it down and it should be good.

 

Should I mark the gear and the cover in anyway to assure it goes back on in the same position?

 

Don't take the chance of un-meshing the gears. Pull the pump off while leaving the housing cover on. Then you can unbolt the cover and slide it right up and off, leaving the top gear in place.

 

But if you're going to go in there and clean the surface the housing mates to, you aren't going to be able to do that with the gear in the way!
Seriously... it's not that big a deal; as long as you get the teeth in the same position; even one tooth off is easily noticeable -- it's 7 degrees of timing gear rotation, after all(14 degrees of timing). And, even if you somehow manage to become one tooth off, the truck can still be started(if it's one tooth retarded, it will barely start and have no power, puff lots of smoke. One tooth advance will be very loud and clattery, and have no power). It's pretty obvious.

 

The gear isn't in the way at all, it's very easy to work around. Did mine this way and have had no issues with it. Use a razor blade to clean off old RTV and wipe down with brake cleaner.

One tooth off means you're wasting time tearing it back down to fix a problem that you never should have had in the first place if done properly. Do it right the first time and be done with it.