You're fortunate to have found a metal on as Don outlined. having done this several times on my numerous 240s, I found that I didn't absolutely need a jack stand, but it is always safer to use them. I used on occasion large wood blocks or equivalent. You only need to raise the body of the car, the wheels don't need to come off the ground. All you need is clearance to position the pan and insert and tighten the bolts. You just have to be sure that the body will not come down into your face!
Be careful and your car engine will look cleaner and air will flow as it was designed and parts will be protected. Jim in San Diego