Zenith replacement chart is in Tech page I helped Phil put together.
Orig 14 L on Star R was Tillotson R-4A
14L Durant 1928 / 29 model 55 Tillotson SP-13A or R-4A
Both model 60's 169.3 cu or 185.0 cu SP-13B

Where Are You From? Ottawa Ontario Canada

Do You own a car built by Durant? 1932 614 sedan made by Dominion Motors

William, Norm's right, you have a lot of options.
The chart on the Tech page was created by Phil Peters and cover just about every engine the company used.

Rick

Where Are You From? Fremont, CA

Do You own a car built by Durant? 1931 Model 619 and 1929 model 60 Roadster