My cakes generally end up being around 4 1/4 to 4 1/2 inches high. I plan on using the SPS system for the first time next Friday. I could only find 4" legs. Someone suggested trimming off some of my cake. How much should I cut off? Does it have to be 4" total or can it be a little over. The cakes will be covered in butter cream and fondant. Do you measure the legs the same as you would with regular dowels? Should they be level with the top of the frosting or a little shorter? I'm always afraid of trying something new especially on such a large cake. All I want is it to make it to the party in one piece.

If the total finished height is 4.25 you should be OK. 4.5, no. With a fondant cake, the legs should be a tiny bit taller that the finished cake, so that there's no pressure at all on the cake - all of the weight is being carried by the legs. And by a tiny bit, I'm talking 1/32 of an inch - not a thing you measure, just the legs should be a bit above the top of the fondant.

No support system should be shorter than the cake. That makes the cake itself carry some of the weight from above and will cause the cake to crack, blow out or crumble/fall.

you can buy 5" legs (they come in the multi-piece set) or the 9" egs and cut them.

I wish I could have but the supply store I was ordering from in FL was sold out and I had to place the order by last Tuesday to get the order by next Thursday one day before I have to start assembling. When I watched Tonednas video on how she stacks her cakes she places the dowels barely below so that the cakes nestles in just a little. I really want to try the cardboard dowels that she uses. They are incredibly inexpensive but I just didn't have time for them to make it here. Thank you for your help Leah.