My 70 trunk is hard to close when opened all the way. It feels like it's going to break when I try and close it. Are there adjustments?

Yes there are adjustments for your decklid. If you look inside the trunk right under the decklid you will see TWO rods that go across to each side. Those rods provide the opening and closing tension on the decklid. One end goes to the actual arm that the decklid bolts too the other end is the adjustment. If you look on the inner wheel well you will see the end that adjusts the tension. The rod should be in a bracket that has three slots. Moving the rod in a different slot reduces the tension. Both right and left rods can be adjusted. Now keep in mind this is a two way street. If the decklid closes tight it opens very easily and vise versa. You want to play with moving the rods into different slots til you have a good tension closing and opening the decklid. I believe the rods on mine are set at, the driver's side is in the middle slot and pass side in the first slot...Eric