273 Timing Marks

Hi All,
I am replacing the harmonic balancer on my 273 and the good folks at Precision Parts who manufacture the Powerbond brand, are happy to re-work a 318 balancer with the correct timing mark but I need to tell them where. I have read in threads that it is 90 degrees different but when I line up the two old 273 balancers I have with a brand new 360 balancer marked at 90/180/270 etc it looks more like 80 degrees, anyone have the exact position of the 273? Thanks, Steve