Mopar Street Rod/Rat Rod Thread

Correct me if I'm wrong but didn't they build it of tubing and sheet metal?
Are you referring to the ramchargers tunnel ram? It was a metal box to mount the carbs, something similar to a header flange on the intake ports..... and rubber hose for the runners, with a couple straps holding it all in place. They could play with runner lengths by changing the hose. (You can see the straps in Scamp Rhondas' photo).
Result? Long rams, and crossrams, with tuned lengths to make torque at a specific rpm.