That is correct, they are solid mounts. Be forewarned, I believe that any of the LS swap engine and trans mounts are not plug and play items. You will have to adjust and/or fine tune the engine/drivetrain alignment and angle to fit your application. I did not get any installation guides from RPM for any of the items I purchased nor did I see any available on their website.
I'm currently doing a test fit and alignment of mine and measuring to see what accessory drive will work with my application. I have some pics of mounts installed, but can't figure out how to upload.
Can send them text or email if interested.