Well, I sucsessfully built a 3800SC that destroyed my friends less than 10k mile getrag, and I only did 2 mods to it, (3.2 pulley and 1.9 rockers).
this graph might help you out. http://www.fiero.nl/forum/Forum2/HTML/087088.html
All of those transmissions but the F35 and F40 6speed bolt to a 3800. The F35 is by far the strongest transmission out of the bunch. On paper its twice as strong as a 6speed, and the 6speed on paper is at least 2.5 times stronger than a getrag.