To answer one question, the bushing size is standard for all trailer springs. However, the wet bolt kit is not. Check if you have a Trailair Equaflex or the Dexter equalizer. Heartland started using Dexter axles last year some time. I think the Dexter kit is different than the Trailair kit ( not absolutely sure ). Shackles can be purchased from a variety of sources. There are different length shackles - measure first. The thicker shackles must be specified with the order of the wet bolt kit. My kit did not come with the thicker shackles. Some thicker shackles come with the wet bolts already pressed in. If not, I pressed mine in with a vice - just make sure that the bolts are straight. If not, you will have difficulty in assembly on the trailer. Buy a couple of extra metal bushings. I have the Trailair Equaflex and the pivot bushings were worn out. The wet bolt kits comes with a wet bolt for this location. The original does not and they are not greased from the factory. SmokeyBare stated that you do not have to remove the wheels to do this but I found that its much easier to have all the wheels removed from one side. As I stated, I replaced the pivot bushing on the equalizer and this is impossible without the wheels off and both axles supported, and again, there is a wet bolt for this location.