ported heads with plugged smog holes

Discussion in 'Fox 5.0 Mustang Tech' started by goldbomb79, Dec 15, 2003.

  1. ok, i have done the smog delete and my ported heads have the hole on each head welded shut. my question is I need to vent my heads still right? I have a set of 302 valve covers with a pcv valve in the drivers side, and I have a oil fill beather cap. should I use these to help my heads breathe?
  2. Well, the heads themselves don't have to breathe. They have holes that vent air from the crankcase to the valve covers. So you should have breathers on at least one valve cover.
    And which hole did you have welded shut? The one on the end for the smog pump? If so, why didn't you just get the bolt and plug from a Ford dealership?
  3. well, believe me I would of just plugged it with a bolt and some thread sealer, but they were welded shut when I bought them. I got a good deal on them so I can't complain. yeah, I know it's venting the crankcase, but the reason I was asking about using like a oil filler breather is because doesn't the 89 5.0 run on a closed loop pcv system? wouldn't it effect my idle if I used a breather. j\w
  4. Well, as long as fresh air can enter the crankcase, either through the breather, or the tube that runs to the throttle body, you should be good.
    So, an open breather on one side and a pcv valve, and your set.
  5. well, I figured it would work, but I just wanted to get some other peoples opinions thanks. should be able to start it up this weekend.