I don't know if you watched the video but they are missing one bushing (TRZ guy on the video says if TRZ didn;t include them you don't need them) plus the bolt kit they sell you with the bushings are grade 8 so they aren't metric. Why do you need them?
I saw the video too, but I think he might have meant grade 8 equivalent. Note he also called them brass bolts. The bolts came from Mike's Montes and I doubt he'd send an SAE bolt kit out if you're needing metrics. But never say never.
#5 cushion isn't supplied because they didn't want to make a metal bushing that big IMO. If you have a 442 and most Cutlass, you likely have that bushing. The rubber one just sits in place. Not bolted in. Maybe not required in every car, but that's them just being lazy I'm betting.
I don't see the point of reduced height bushings. Get the regular polys if solid is what you want. Or fleming442 's hockey pucks that he loves so much. What about the radiator support? I may have missed something.
I was just sorta curious as to what others had to say about them and what everyone was using. If I went solid, I planned on using the standard height bushing, although the other *could* have been a possibility but after a little consideration, I think I'll steer clear of those. Price point wise, hockey pucks are hard to beat. I've seen a prothane poly set for around $105 on ebay. The car definitely needs mounts regardless.
As a word of caution, you may have some rotted mounts too. Don’t be surprised to pull the old bushings out and don’t have any frame or body to mount to in that location. Even some really clean cars suffer from it.