So I recently purchased a 1990 SS Mark V with the 510 table and fence system. I was having a hellofa time getting it to roll around on the floor. One of the casters wouldn't pivot when I would push it around and so it made it a pain to move. I love the retracting brackets though wow. Those are nice. So anyway I deemed a caster upgrade worth the expense and ventured onto eBay. Luckily there was a set up for auction and I ended up winning but not saving much if any if I had bought them directly from SS. So I received them but there were no installation instructions with them. A little effort on Google and I was back in business. The casters are considerably larger than the old ones. The old ones are a hard plastic where the new ones have a softer rubber type wheel and the steel just seems heavier duty. The install went well. I was able to follow the instructions and they made since. I really gnarled up the old bolts getting the retraction brackets off so back to eBay where I found that stainless steel bolt set for the SS that has all the bolts to upgrade the SS to stainless steel. Very nice kit. Maybe I should do a review on that one too. With new hardware and my trusty dusty google instructions I removed the retraction brackets and then used the templates to locate the new holes for the brackets. Drilled them per the instructions and luckily there is some play in the bolts and holes so the a perfect line up was not necessary. Bolted it all back up and they are perfect. Perfect in every way. The SS glides on them. They pivot with ease. The casters role over saw dust and wood chips without hanging up. Very happy. So when it comes to the caster upgrade I would recommend the money if you are able to afford it. 5 stars in my book.