Boy I will tell you, them 2925 S/V intakes always impress me on whatever I have used them on. My 1st 406 ran great with one, my 358 ran well with one and my Vortec 406 screamed with a tiny cam to 10 sec territory with a Super Victor. It was just too bad the Vic Jr. did so poorly this year. My car was a dog with it but my buddies car ran super good with the Jr. Guess it was not a good match for my combo.Good points 1980RS, and sometimes the term "porting" is used but "gasket matching" is actually done, and in some/many cases it's actually ruined, or hurt the engine potential performance more than it helped in many cases. I also have found in several cases that true Dual Planes can be "under carbed" and open plenums somewhat over carbed considering the engines requirements and effective rpm.
Some intakes are just so bad with casting shift and horrible port alignment it's not even worth putting the time in them, they are "New" and fuked right OOTB.
Here's 2 dyno sheets, same engine/dyno/fuel/timing/temps/carb, 4 hrs apart on the same day. Each intake was prepped by me and tuned as well, spacer(s) combo for each intake was optimized.
Not hard to see the trends by the rpm's in where the DP and OP like to operate in, it depends what the engine is going in and used for. The dual plane was getting funky in the upper rpms, even though the 333 cubes, without the spacers on the dual plane, the numbers were more spread apart.
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