Hoping someone can help me with this. I am currently working on a 1967 Firebird with a 3.8 OHC engine. The oil restrictor that is in it, is the original one that was known to have the orifice too large that feeds the lifter galley. This is the information that I found on the internet, and was hoping someone here can verify the info.
2) This is where the 1967 Service Manual becomes valuable! It describes, in words and pictures, how this system works. There’s a passage through the head with the restrictor, it’s between cylinders 2 and 3, and it is a piece of tubing about 2 inches long with an hourglass-shaped crimp in the middle of it that is about 1/8? internal diameter. It then has an .080? hole drilled in the side of the crimp, and the sizing of both the drilled hole and the hourglass crimp are critical to the flow volume and the pressure of the oil being fed to both the camshaft AND to the lash adjusters (lifters). Sometimes when poking around the holes and passages of a head being cleaned, these are damaged. They are also a bit fragile to try to remove from a head that hasn’t been hot-tanked enough to let it come loose.
So I had one made to the dimensions here. I'm particularly concerned about the center hole. The original tube measured about .190" through the center. I had the new made to .125" through the center. Can anyone confirm these dimensions.
