I just changed my 54 rubber mounts for urethane mounts...they sandwich the cross member and have nothing to break loose but the grade 8 thru bolt. I would think they would be tougher than the stock 50 mounts and not subject to oil contamination.
One thing I did note....there was no urethane single front mount available that I could find. The urethane mounts are very rigid and don't pull down as easily as the stock rubber mounts. I torqued mine to 65 ft-lbs.
Can't speak to the problems you might encounter with a cross member change but it seems like a viable alternative.
Dave
