Who makes a 340/360 thermoquad style aluminum intake

They make block-off plates for the EGR.

Everybody used to make spread-bore dual-planes. But the factory intake works very,very,well. I wouldn't swap it out just to save a few pounds.And I can't say you will be happier with any aluminum intake on a factory engine. That 71 C.I. intake is a gem.

But if you have your heart set on an aluminum intake, I checked the PAW catalog, and found examples from Edelbrock,Holley,Wiand, Offenhauser, and MaMopar; some with,some without, EGR.