I have worked on NYC cabs and police vehicles during the 1970’s and 1980’s. Most were MOPARS 440 400 360318’s and some 225’s. At every 100k timing chains were replaced. When the chains snapped or the plastic cam gears fell apart we had to replace push rods send the heads out and sometimes the cam and lifters replaced. I worked on thousands of these MOPARS and always used the timing marks and lined harmonic balancer. No never used these tools. I never had an issue with this procedure. 54 years later still working on MOPARS. I never saw these tools to find TDC.