Hate to be the bearer of bad news but if you drilled a hole in the intake and went through the water passage, a new intake may be the least of your worries.
You will need to remove the intake and make sure the hole only went through the intake. If it went farther you need a new engine.
If it only went through the intake - Then you will want to drop the oil out ASAP. Bolt on a replacement intake, The 4.3 is very common, you should be able to get an intake fairly easy from a salvage or you-pull-it place. No good way to fix the hole that I would trust unless you can have it welded, which would cost more than a used intake.
Fill with clean cheap oil. Run it just long enough to get the oil moving and change it and the filter. You are trying to flush the coolant out of the bearings before it destroys them. You will want to do that again with a commercial engine flush as well.
If you get the coolant out of the bearings and oil system, Flush the cooling system and are lucky, the engine might be okay. Even then if the chips from drilling went into the cam or gearing it still may destroy it.
I have seen 4.3's with leaking intake gaskets turn the oil into a milkshake and survive to run a lot of miles, I have also seen them fail soon after they were repaired.
Tuesday, December 20th, 2016 AT 12:22 PM