I have used dragsix’s method for 60+ years and it’s always right. Remember as noted by Fibonacci above, the timing marks will appear in the window twice as you rotate to find TDC. Many see the marks and falsely assume the engine is at the correct place when it’s actually 180* out. Do it right and you will be running in no time. Good luck.

Martin
'62 Chevy C-10 Stepside Shortbed (Restomod in progress)
'47 Chevy 3100 5 Window (long term project)
‘65 Chevy Biscayne (Emily)
‘39 Dodge Business Coupe (Clarence)
“I fought the law and the law won" now I are a retired one!
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USAF 1965-1969 Weather Observation Tech (I got paid to look at the clouds)