Marty - I've had the same experience. For front or rear lifts, you need at least a foot or more initial clearance to just get a floor jack started. The problem is your lift points are waaay under the very low body - you can't pump the jack handle. Then the first 50 pumps will only gain you a tiny rise until you can achieve some significant lift to allow the handle to full swing.
You need some low-rise ramps to get some initial clearance. Pep Boys or 2 x 8s work nice.
For side lifts, no issue. Just be sure you lift from directly under the sub-frame. Where all those pesky little sheet metal flanges are located. Try to lift on the small flats between the flanges and directly under the floor reenforcing beam. For this, I often use my sons screwjack from an old Datsun pickup. It has a flange locating feature on top that fits perfectly betweeen the flanges and pushes directly on the floor beam. Little blocks of wood are often employed to achieve a good pushing surface. Check twice - jack once. Be careful and Enjoy.
