Thanks home brew. I had missed that "rear axle to frame clearance" thread and it's just what I need to know. The original has a lot of suspension travel as well as a lot of ground clearance.
It looks like Deuce has about 4" in that C'd frame in his journal and that's also what was mentioned in that thread. Even when the body was on the frame, this Olds had almost double that much clearance to the stop. With the body off, it has 9" from axle to the rubber bumper and 12" from axle to the frame. (The rubber stop is positioned on the forward sloping part of the frame). This is encouraging.
I remember the first time I drove the Olds, it was remarkable how much that suspension absorbed. There is a set of railroad tracks in Leitchfield, KY that used to eat tourists' cars, before they fixed it. You go up a hump of about a car length and it suddenly flattens out to go over the tracks. There was nothing between the tracks but crumbled asphalt. Natives going into town would crawl over the tracks. Tourists heading out toward the lake would launch up that hump and slam down between the tracks. That Olds simply rose up and settled, no matter which way you went. It kind of wallowed side to side in the rear if you hit the tracks at an angle. Highways and travel patterns have changed a lot since its era.