The part about pointing out that they are aluminum is useless... I'm certain that all Edelbrock intakes are aluminum. Anyway, the 6 pack intake was described in an article in Muscle Car Review magazine, Sept 2008, page 70.
Casting number 3412046, and weighing less than 1/2 of the iron replacements that Chrysler made for the 1970 model year. I had one, and it was effing heavy, easily more than 40 pounds.
Chrysler switched from contracting the intakes from Edelbrock to making them to save about 1/3rd th 1/2 off the cost per unit, that is alot of money.
About 3500 were made by Edelbrock, and I'm very happy to have one on my engine. I wanted one for about 7 years before I got mine.
On the topic of Edelbrock intakes, NHRA accepted them as factory stock. That is pretty cool imho. The LD4B and CH4B intakes, and the 2 piece hemi intake were given Chrysler part numbers too.
http://justacarguy.blogspot.com/2006/11/mopar-six-pack.html
