I think that this is a bit off:
Quote:
Originally Posted by jhein
So if the consensus is that quality of these castings are no worse than factory castings, then there's no reason not consider one.
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I think the consensus is that factory ones were not perfect, and that core shift (if that's what we might call it) can be observed on them all;
I believe what is being implied (certainly in the quote) is that all core shift is equal.
But it is not.
This is essentially a comparison of the worst to the repops.
Also, now that I'm thinking about it again (I thought I mentioned this already, but cannot see the comment);
I do seem to recall that the consensus was that these repops are all essentially the same part with revised part numbers;
If my memory serves me, the original 1972 intake had the highest height for the plenum directly under the carburetor mounting flange - and these all measured as being based off the 1972 part (which I believe was also what GM did with later service replacement parts).
I believe that generally the OEM intakes had the least core shift (or runner misalignment) and that the OEM 1969-1971 intakes had the best flow because of the lower plenum under the carb.
Surely no OEM (or SR intake for that matter) required welding to seal up holes in the runner - as was the case in the intake from the video.
As to the other query:
Quote:
Originally Posted by jhein
... So then the question is do they perform better than a factory iron intake as cast, or would they need to be ported for any performance benefit?
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I believe the consensus is:
NO
The intake runners were made taller to align with the intake runners of the 69-72 round port heads.
I believe that even when ported, you need to match to the heads to maximize any gains.
I am confident I will be corrected if I am off on any of that.