I used the kit that came with my tub..........but I'm assuming it is the same kit that you buy from KW or Walck's. It is really nothing spectacular and I still had to trim down several spacers to get the tub to sit level on the frame.
In hindsight, I would definately just do what others have said and buy a boat roller and cut my own spacers or use an old tire. The bolts in the kit were just regular zinc plated bolts (not even stainless!!) with nylon loc-nuts. All together, you might have $35 in the rollers, bolts, nuts and washers if you buy them yourself.
To cut/trim the spacers, I had luck with a few different methods. A bandsaw works well if you need a thick (3/4" or more) chunk and you make a jig to hold it. Also, you can take a hacksaw blade and heat it up with a torch and cut through pretty easy. To shave off small amounts for fine tuning the thickness (1/8" or less) I had good luck with a belt sanding machine and an 80 grit belt. Be prepared to take the spacers in and out several times to get the tub sitting level.
One last thing, when you get the spacers finished and the tub sitting level and you are ready to take the tub off for paint, make sure you mark what spacer goes where!!!! Otherwise someone helping you (like your brother-in-law and best friend) may walk over and gather up all the body mounts off the frame and toss them into an oil can before you can write down which spacer goes where...
All part of the fun!
