Looks like the 5400# lever type so with the lathe being in the 6000 to 7000# range the tool is not to blame. Lathe was built for the US Navy in 1942 and is a heavy dude. Note the crankshaft mounted up in the chuck.

[img]https://i.postimg.cc/0zGYpqvB/IMG-5261.jpg[/img]


Evan