[JimFB400HO]

5691676 is the casting number for power steering boxes for many GM cars for several years.

Here's a description of it on the CRG (Camaro Research Group): " The power steering box was casting 5691676. Many different gearsets for many different applications were installed in those castings. There are no permanent markings on the gearbox to identify the original usage of a box."" https://www.camaros.org/suspen.shtml#steer

Someone here may be able to get you closer to an answer by manually determining the number of turns lock to lock.