Bolts for tranny mount?

Vehicle we are dealing with here:

85 wagoneer
2.5 engine
904 tranny
229 Tranfer case.

After my last outing I developed a very bad driveline vibe. Come to find out my crossmember on the driver side was loose along with the two bolts that hold the top of my tranny mount to my tranny. The passenger side bolt was loose but the driver side was tight. As soon as I took out the tight bolt the opposite bolt fell right out. STRIPPED!! I have some good threads left on the tranny with even better threads the deeper you go.
My problem is the bolts are pretty bad and I cannot find a parts store that supplies these. They are almost triangle like but round at the same time. No pictures available. Sorry.
So what are my options. Are these available at the dealer and if so do you think that they have a longer version so I can grab more of the threads on the tranny. Will I have to drill and tap it out to a different size? Get new bolts with good threads and put them in the best I can? Any opinions are appreciated. Thanks.

Kim.

Problem taken care of.

Kim.

may I ask how you solved it? I have an 87 with a missing trans mount bolt for the same reasons.

I went to AdvanceAutoParts and got some 7/16 bolts, I think that was the size, that were about 2.25 inches long. Used a washer and it fit good and tightened up pretty good. Hopefully it holds. I have my brakes apart right now so it will be a couple of days before I can test it out and see if the vibe is gone.

Kim.