Mopar Action just did a comparison between five intake manifolds. They thought all five would work good on their engine (stroked 440 with Edelbrock heads). The old six pack did OK.
Well OK it came fourth out of those five but there was VERY LITTLE between them.
The top intake was the Edelbrock Victor which is a VERY tall single plane intake that will not fit under a stock hood so that one I would have to rule out in my application.
Out of the four left the winner was the Mopar M1.
The M1 is a singe plane design that makes more torque lower down than I would have thought. A good intake. However it only made 2-hp and 10-lbs (585hp/625lbs) more than the six pack! On a less powerful engine the difference would be even less.
The other intake to beat the six pack (just) was the Holley Street Dominator which I used to use before I rebuilt the engine. That made exactly the same power but 7-lbs more torque.
The last manifold was an Edelbrock Torker II. It was well down on the others but I am not sure it suited the cam rpm range?
So out of the bunch that would fit under a stock hood the 35 year old six pack came close to these others when it came to PEAK power and torque.
What the magazine does not show you is how well the manifolds worked over the FULL rpm range. That is a pity because just looking at peak numbers can be misleading.
I would also have liked to have seen how the Performer RPM manifold worked in comparison. It looks from the outside to be a single 4bbl version of the six pack intake. I don't know how it differs internally.
D.