I put one in on an engine stand (400 olds) the proper way, too. Which requires clamping and trimming. At the end I could not accept the required turing torque with the finished product. Ripped it out and put in a modern replacement style and will never waste my time on a rope again.

I can't imagine doing this in a car. The crank has to come out.

I'll be the first to bet you will end up doing it with a replacement seal.