Actually HF sell a Cross Beam Jack that is a pale imitation of this imaginative diy alternative. Problem with the diy version is stability but manageable with jack stands.
Steel Floor Jack Cross Beam
Some cross beams are adjustable for width. I use this specific jack -even on a full size diesel pick up - it is very sturdy and stable.It would be easy to widen to the dimensions shown in the diy alternative here.
http://www.garagejournal.com/forum/showthread.php?t=217325&showall=1
I also use 2 long frame HF jacks simultaneously You pump both together evenly ! The long frame floor jacks are no longer sold at HF but alternative brands are available elsewhere.
http://www.northerntool.com/shop/tools/product_200329613_200329613?cm_mmc=Google-pla-_-Auto%20Repair-_-Jacks-_-144795&ci_src=17588969&ci_sku=144795&gclid=CNjxof3d5LkCFYl_Qgod-mYAdw
Threaded Mode
