Heya Phil,
I've never seen the airbox in an Amazon, just the pancake two-bolt and tall three-bolt filters starting on most '67 models. So I guess that'd be right; 140's had the black box...and the, to quote Mr. Downs I think, "pipefitters nightmare" manifold, plus the heat riser.
There is a local 122 I tinker with that has the big hole stamped in the front valance for the air hose to feed through, but alas, no box. The owner says the car came over from Sweden on that new? Swedish Volvo delivery program.
No clearance issues under my hood but there was a bit of a restriction of air at WOT with velocity stacks uh,...stacked in there:o)
RF runs much better at stop lights in the hot Summer and, is it my imagination or have I picked up a half a horse by using slightly cooler air? Heh.
S.