Will Atlas Containers Fit Lionel 6-81466 (BNSF Maxi-Stack Pair)?

No. Atlas containers are scale so they are too big in width and length to fit in your cars. 

Paul, the "Maxi-Stacks" are essentially in the Lionel 027 line.  If you get an "Engineer's Scale" at your local office supply store (a ruler in triangular cross-section with six scales on it) the "50" scale will illustrate this.  ("50" is a scale with 50 marks in each inch, every 20th numbered with the even numbers 2, 4, etc; every tenth mark being a long line, every fifth mark a shorter line; so-called because it is used to draw road plans at a scale of 1" on the plan represents 50 feet on the ground (or in real life full size).  So then the numbers 2, 4, etc.  actually represent 20 feet, 40 feet, etc.  Real track plans are also drawn using this scale, but as they are drawn at a scale of 1" equals 100 feet, each division of the 50-scale represents 2 feet.

For us, similarly we would use the 50-scale as a "5-scale"--in this case the numbers 2, 4, etc. would represent 2, 4, etc scale feet on the model, and each of the 10 divisions would indicate a tenth of a foot (1.2").  This is quite convenient because, for example, you might see that the 2" width of the Maxi-Stack is measured as 10 scale-feet, which it more or less is in the prototype.  I happened to have done this in the last week,  to the very BNSF car you are mentioning.  The height was of interest to me, because in my case to be an 027 car here, it would have to transit the proposed postwar lift bridge (never produced until the modern era); it did with at least 1/16" to spare, possibly twice that (temporary approach track improvised in dim light).

All in all, I think these containers/stack cars fit well into the 027 world, even though they run on O-scale trucks (they run on high centerplate trucks, which may be possible to change, altho my last try with a 5-platform spine TTX (K-Line) reduced it to 3-platforms and increased its radius from O31 to O72.  But it did look really great.  :-)  I'm not sure this BNSF deep-well Maxi needs this treatment.  You can of course measure the truck with the 40 edge of the scale rule (used as a 4-scale or obtain also an "Architect's Scale" which measures both feet plus inches in one).

Now this two-platform car as it stands still has a relation to real-life in 5-scale.  The placard height on double-stacks is 20'-2", IIRC.  What you have is that the spring travel on freight trucks is typically 4" vertically:  that is, 2" travel each way from nominal center.  So the nominal center is arranged to be at a nominal marked load weight (I recall loaded weight max per container about 80,000 pounds based on my highway observations-- this does not comply with present Federal limits for Interstate highways (72,000 pounds including the carrying frame, it's 8-wheel bogie and the 8-wheel bogie of the tractor, plus part tractor(ie, less 8000 pounds on steering axle)).  I guess more of this stuff is moving under overweight permit than I realized.  But you will realize that empty containers in train will tend to have roof surfaces at 20'-2".  These surfaces must have an electrical clearances in air of 9"; in addition, wire sag of about 1" in hot weather takes the remaining 1".  Now at this time Fed Hwys and the AREA had agreed on measures to accommodate a wire height of 21-feet, more or less.  Now if you were to use a GG1 working under wire, in an 027 world, the ideal wire height of 5-1/4" would represent a high wire at 26' very closely, so it is not out of place.  Nor would it be out of place in an O-scale world.

[I should add parenthetically here that I have an (early*) Lionel Husky Stack or twofer same that fits into the O-scale (1/4" foot) world. particularly as to height and width (more work in dim light, plus on a rickety step ladder).  But its length is shortened; I cannot recall if it is as the 20" passenger car is to the 21" car.  The issue is it would not otherwise clear the switch box on certain existing layouts with O72 tinplate switches.  So it will not accept, lengthwise, many if not all scale containers (20-footers might be okay, one end)  The problem with many scale deep-well cars, is they are only scale height when they are on scale trucks.  The 1/8"-inch or more allowance for high-rail flanges can really wreck the situation with overhead wire for GG1's, particularly if running one of a pair off the wire on a single loop, and the other off TMCC, at least in my limited experience.  Well, I once designed concept modifications to a Metroliner maintenance yard to accommodate light running repairs to the Amtrak GG1's and the entire wire plant for the yard as changed-- so naturally I'm a rivet counter on GG1's.]

--Frank   *Note: Recent change in truck philosophy at Lionel may change heights.

You can put 1:64th scale intermodal shipping containers in the Lionel O gauge GUNDERSON MAXI-STACK well-cars. 

Andrew

http://www.desplaineshobbies.c.../S-Scale-Intermodal/