I don't know about the G52 specifically, but I would go in assuming you will have to modify the floorboard. Not hard to do. The bellhousing fits a 22R block, and normal 22R clutch, so no worries there. You may need to modify driveshafts but I tend to think not. I would be very uncertain about the crossmember; you should be able to modify the stocker though if you need to.
HTH!

-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