kplange

I have a couple of pin hole coolant leaks in my intake manifold on my '81 Olds 307. I ordered and received a replacement manifold from Edelbrock this week. Part 3711, supposedly for this engine. While the new manifold appears to be almost identical to the old one, just before I went to mount it, I noticed two objects screwed into the plenum of the old factory manifold. The new manifold has two holes in the same approximate location, but they are smaller and not threaded. What are these attachments and are they necessary?

joe_padavano

This question comes up frequently. Those are EGR nozzles that help mix the exhaust gas with the inlet flow when the EGR is operating. The E-brock manifold doesn't include this feature because, frankly, they don't have to certify to the same emissions standards as the OEMs, and most of their manifolds go on older cars where the EGR isn't even functional. or needed. Don't worry about them.

kplange

Thanks Joe. That was the answer that I was hoping to get. I got the same advice from a neighbor that happened to be walking by, but your response was more technical. Now I know what these were called and what purpose they served. Now I can go ahead and complete the installation. Much appreciated!

64Rocket

If you feel you want or need them, just thread the holes and install the nipples.

Gene