727 trans mount question

I thought I knew the answer to this, but I guess not. I just put a 360 block/727 in my '65 using original 273 mounts (adapted to the 340/360 ears), and the '65 OEM 2" thick rubber insulators with metal flanges. The car had a B727 in it when I had my 451 in it and the trans mount bolted right up, but the custom mounts were completely different. I already pounded the body seam flat in the tunnel but I cant get the tailshaft high enough in the tunnel to get the trans crossmember bolted in. Do they make shorter trans mounts? Mine is about 1.5 inches above the crossmember. Even with the trans mount removed I was barely able to bolt up the empty crossmember. Do I need to slot the crossmember holes and get it down 1/2 inch and run a short mount? I dont remember having this problem back in the day of my 340/727 but that was using later 1" biscuit mounts ( I think). I have had so many combos in this car Im losing track of what went with what. Thanks.