What I've always done is to first attach the mount to the crossmember with the transmission lowered a few inches then raise it with a floor jack while using a long drift punch or alignment tool to help to line one of the holes up. When you get it close enough you should be able to get one of the bolts started and then I go to the other side and do the same thing. With the alignment tool still in the hole pull it in the direction to align the the hole up as perfectly as you can. Then tighten the bolt that you started on that side. It will then draw the crossmember up to the frame. Do the same thing on the other side. Good luck, I hope it works for you as it's always worked for me.