I have a need to buy a gantry crane for my shop.  I would like to also be able to use it in the garage attached to my house, which has a lower ceiling.  Under the garage door opener track is 96".  To be able to roll out through the garage door, my limit is 83" tall.  I need something in the 1-2ton range, about 90-100" between the legs  mostly for picking up engines and heavy crap out of the bed of a pickup truck.

Does anybody know anywhere to buy a gantry crane similar to this style that can accommodate the lower ceiling height?

I'm also open to modifying an existing one.  Is it as simple as drilling some holes 6" lower and chopping off the top of the lower legs to allow the thing to sit down lower?

OP,,Just take the "top" portion and chain it to the rafters as long as they are strong enough to handle the loads you'll need to lift. It will still give you left to right to left movement and it can be done with a 4" piece of steel Ibeam along with the roller dolly.

I want to move the gantry between my garage and my shop in the back yard.  Chaining it in place won't do.
And the ceiling in the garage has sheetrock and insulation, with hardwood floors on the top side.  I'm not jacking that up to wrap chains around the rafters.

But 3 points for creativity.

They have other options as well

https://www.grainger.com/product/Adjustable-Gantry-Crane-Fixed-48TC25

Lots of vendors with adjustable height rigs like this.  Some in aluminum, nice if moving between locations.