For anyone still wondering: No, you don't need to solder anything. All N64 cartridge connectors (from any region) are the same and none of them require soldering at all. They just plug in and out. I replaced a couple of them myself and when I found out that some cheap knockoff cartridge connectors (who claim to be N64 replacement parts despite having 50 pins with the wrong spacing) are causing people trouble and confusion, I did a good amount of research all over the Internet, only to find out that there are no regional differences when it comes to cartridge connectors for the N64, but I also found that there are a lot of people who believe there is (simply, because their parts don't match the already false description of guides like this one). I did replace a few of those connectors myself (mostly in PAL consoles, but also in one NTSC-J console) and I talked to people who did the same with NTSC-U consoles. I looked at dozens of Youtube videos. And it all came down to 48-pin plug-in cartridge connectors.