There is a rear transmission mount on the three speed tranny, uses two of the lower bolts that hold ring on ball joint at rear of tranny.
I don't know if your 54 still uses bolt together u-joint or not. If it does they only used 1/4 inch bolts to hold it together. With extra power of 261 it might have come apart. Mine did one summer afternoon. Scored up ball housing pretty good.
How did water pump work out?
