Sears has an adapter that goes between the ratchet and socket to measure
torque:

<<http://www.sears.com/sr/javasr/product.do?
BV_UseBVCookie=Yes&vertical=TOOL&pid=00944599000&subcat=Torque+Wrenches>>

Or try:

http://tinyurl.com/7m45f

It doesn't say what the capacity of this device is, but I assume it's at
least 75 lb.

- Kevin