What about going with a Dobinson spring kit. The guy is on here David Otero. They are based in Florida, but ship to US address. Use seawings or whichever importer to get it across.
Dobinsons make a huge about of springs for the Australian and 4x4 markets.
I just got a lift through them for the 80 series, the amount of spring combinations were almost staggering, but David had lots of time to email me with info on all of them. Ended up with a progressive rate coil that feels great and similar price to the OME kits with some more features. Always quick to respond back with questions. So far I'm really liking the feel of the new coils I got. Anyways, just another avenue to check out. Here is the link for the 60.
Landcruiser 60 Series (1980 - 1990) - FJ60, FJ62, HJ60, HJ61 - https://www.dobinsonsprings.com