You can get a bumper fitting which either may work (if its rounded somewhat) or could inspire one which would. Hi-Lift stores stock 'em. But use it at the frame mounts, or you will definitely twist your bumper. Even there, its a tad weak stock.

You could weld square tubing to insert the jack into, affixing it to the receiver hitch crossbar. The idea is to have rigid places to lift at each corner of the vehicle rather than lifting a whole end (scary).

-Bill
'87 4Runner w/ '96 5VZ-FE, 'Red Chili II'
'97 Taco XtraCab 3RZ-FE, 'BlackBean'
TLCA # 13257, Rising Sun 4x4 Club Land Use Coordinator
"He who stops being better stops being good." -Oliver Cromwell