Best plan is to not use urethane for this purpose. I am glad that it is expensive or I would have been tempted to use it. I thought better of it, as I was thinking about the poor guy who had to come in behind me (most likely me). That stuff does not give up holding on.
Carl

1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission