66 Dart Headliner Help

Started to prepare to install the headliner. Its a 2 dr hardtop. I installed insulation on the inside and I put the bows thru the pockets on the headliner. SO heres the question I have.
The pockets or sleeves that the bows slide into, first there are 6 and I only removing 5 bows. 2nd, since the headliner gets wider at the back the sleeves are longer. Now the first 3 sleeves starting at the front I cut a 1" long slot from each end on both sides. Im not sure how far i should cut but I watched a video that said 1". Now the back sleeves the bows arent even long enough to stick out on either end. Im guessing that there is at least 6" on both sides that over hang the bows. So how far do i cut or how do i know? I want to get this liner in during this weekend so your help in directing me to either a thread that would explain that or a video to watch would be great. Here are some pics to help explain what I probably poorly described! Ive drawn a white line to help show how much longer the back sleeves are.
20180914_204936.jpg 20180914_204936_LI.jpg 20180914_204948.jpg 20180914_204948_LI.jpg

Thanks Rod