First, make diamond stress plates (shaped like this more or less: <> , at least not straight up and down on the edges) and weld them to your slider outriggers. Then weld them to the frame. Don't weld the points, just the angles. You'll be just fine.

Actually, you'll probably be just fine even if you don't do all that... but just in case...

-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