Big Block/A-518

Wont the 518 fall apart behind a 440 making any kind of HP and torque???
I have a v10 Dodge pick up from the 90's. What trans is behind the V10.
270,000 miles and still haulin!!!
Body is shot but I have been haiulin cars for 10 years and have never serviced the trans
Is this a 518??
You know, now that we've covered what it takes to get one into the car and working, I have some other things I'm wondering about. How much power can these things handle in stock form? Is it the same as a 727 with that, cuz I've heard that 727s can handle 700 HP with the stock hardware in them. Is the overdrive clutch pack and planetary strong and able to withstand top speed-full throttle-6000 plus RPM, or is it like the GM ODs where OD is only for light load cruising? If I place the shifter in 1st gear, (stock unmodified trans) will it stay in first regardless of RPM or is there any kind of over ride that will make it shift at some point?
Has anyone found what the limits of these things are, stock or modified?