polyurethane engine and transmission mounts

[wpavlis]

I am in the process of getting all the parts together to replace the engine in my 68. I am putting in a 350 that should make a little less than 300HP and keeping the column shift 3 speed. What are peoples opinions on using the Polyurethane vs rubber engine and transmission mounts. I have had trouble finding poly transmission mounts. I would think you want them all the same. Any opinions and/or experience would be appreciated. Thanks,