What OD trans to hold 700 ft lbs?

How much butchering to the tunnel did you have to do since its a pretty big transmission?
Another words, would I be looking at totally remaking the tunnel?
I guess it doesn't matter much, just curious.

Any major gotcha's to look out for with the 518 swap?[/QUOTE]

On my car I decided that I dont want anything to hang down below the frame , because I am setting it down in the weeds pro-touring style.So I moved my engine and tranny up quite a bit. My tunnel will have to be moved up and the upper crossmember at the rear is custom , the advantage to that is the lower crossmember will remain stock bolt in. I dont want anything personally hanging down ,including the exhaust or oil pan,been there done that with putting holes in a pan , no fun.My stock pan 518 hung down as low as the 727 with a deep pan. So its worth a little welding and cutting to me.

My tranny is a non -lock up and you can use a convertor from a 727 with those. Of course make sure its a 518RH . H meaning hydraulic . RE the E means electronic controlled governor.
518's require larger tranny cooler lines versus the 727's too.