My suspension is from space, custom a-arms to allow second gen spindles and stuff. A bunch of shit you probably don't want to deal with.
The quality of Jarek's mounts is outstanding, just holding one is awe inspiring.
It's not in yet so I can't comment on the performance and durability but I'm going to start that swap this month.
As long as it ran fine I'd not worry about it. What I would do is replace the cover and make sure there is no debris in the head/valvetrain while its off. Don't want to plug up an oil passage somewhere. A used cover from a JY would be cheap and would likely be just as dirty so it wouldn't have one clean one and one dirty one on it. Heck, I probably have a rear cover here if you need it.