Howdy, first time rebuilding classic car, have a '69 Polara, solid but gutted. Pulled the old motor and tranny, sent 727 torqueflight to get rebuilt, bought rebuilt 383 from '69 roadrunner, bored .30, flat top pistons, purple shaft cam kit, 906 P&P heads w/ valve/spring job, edlebrock 383 perf. intake, crank shaved .10, clevite bottom end kit, new timing gears & chain, set up for nitrous...no carb yet, all I can think of now. My questions right now are few and probably simple.

First off, I can easily see the heads have been ported, except for the center ports...again I am unfamiliar with carb motors, and still learning in general so apologize if I sound too newb. So the center "ports" on my 906 heads look like its 40+ years old,(rust/corrosion/coke) while the rest looks spankn new...Whats up with that?

Second question, also head related, when I mock up my intake manifold, there are gaps on the inside tops of the same center ports of the heads. The manifold matches up with the outer two ports perfectly, and the two center ports, which looks like a upside down "U" with a small square port in it. Well the bottom part of the "U" is exceeding my intake manifolds hight, and the valley pan's. I did do minor research on the heads and read that these were open chamber, is that what Im looking at? Just looks wrong, lol I dunno... Help appreciated, thanks.

 

Welcome!

The center port you are referring to is simply a heat riser and doesn't see any air/fuel mixture so there is no need for it to be ported. The "U" shape you are referring to is part of the head design and is not intended to be covered by the intake manifold.

The term "Open Chamber Head" refers to combustion chamber. Open Chamber Heads have a larger chamber than a Closed Chamber Head. Here's some good reading for you:

http://www.forabodiesonly.com/mopar/...ad.php?t=62122

 

You say the heads have been ported. Can you find out if the heads were milled too? Meaning "resurfaced" on the cylinder mating surface. If material has been removed, then there may be an issue with intake fitment since you say you are "mocking-up" an intake. For every .010" of material removed, you must remove .0123" of material from the intake face of the head, or the intake. Just a heads-up in case you have some fitment issues. Also, we 383 guys have had issues with the valley pan and using the paper gaskets that come with some of the kits. Most of us have agreed that you throw the paper gaskets away and just use a sealant around the intake ports. My preference is Permatex "Hylomar". There is another thread here if you do have sealing issues on a 383 intake.

 

Thanks guys