I may have misunderstood tbrenner's question about the mushroom. I was referring to those of us putting just the intake mushroom, not the whole filter from a deuce and a half. I was just wondering if the mushroom and necessary reducer produced additional restriction. I wouldn't have needed it if the dad blasted squirrels would leave me alone.
Actually if you think about it, both have the 465 engine or the same displacement of I think offhand is 478 cubic inches. Given a max RPM of 2600 you would be drawing the same amount of air. The engines with turbos might draw a little more but I don't think it would be that much more. I agree the larger 5 ton air filter is oversized to reduce the frequency of cleaning.
I also avoid back blowing the air filter, I just shake it out every so often as part of routine mantenance. I've never had the indicator move so I don't know that it even works for sure.
As far as price on the 5 ton filters, Saturn definitely has the best price by far. My only fear is that some day they will no longer be made.