Hello trevor here again.
Sorry that didn't work out with windsor fox.
Anyways I've found an other t-5 crossmember at mustnagsplus.com but it's the same deal. Not listed as for the tremec.
What I would suggest is that since the tremec is installed in the 87 that you remove the eng./trans combo and before yo go attemmpting to install it in your 65, obtain another trans mount from another car the same as your donor car. i.e. 5.0 5-speed. Or bring your tremec mount from your car to the other car that resembles your donor car. What I'm wondering is if it may be possible that the t-5 mount is the same as the tremec t-5 mount that you are looking for. If the tremec was installed in the 87 with out the need for an aftermarket tremec-specific mount then the normal t-5 mount will work just fine in your car. What I'm trying to say is if the mounting points for both t-5 and tremec tranny are the same then this problem is no more!
I hope I'm clean in my explanation.
Trevor