I never have, I just use an old engine and transmission. But I can see the advantages by not having to lift a heavy block in and out a zillion times. Like Big Truck Driver said one disadvantage might be that they are too light to get the suspension loaded. I have also heard that heavy items like big headers can sag somewhat hanging on the side of them.

I think if the price came down I might be tempted to try one just because, but I think they run about $ 300 (?) so I don't need one that bad. I guess if you were a shop installing the same brand engine time and time again one might make sense though.

Don