Suzuki 2 Strokes

Hi!
I am rebuilding a Suzuki GT 550 1974 model M. The engine had a high mileage so I found the crankshaft and gearbox bearings to renew. No problem for crankshaft because I have a very valid resource in Germany while I met some problems about gearbox bearings. I found 3 bearings at CMSNL as genuine
parts but the Koyo bearing on countershaft (side clutch) is discontinued from long time. On transmission table it's number 19. This bearing is a NR 6306 (one shield) and has a pin to stop possible rotation on its housing. I bought this bearing Koyo "made in Japan" in USA (standard bearing) and I provided to insert the pin in correct position. Not hand made operation! When I finished this job I had a doubt. Are gearbox bearings standard or C3? I presume they are standard because all bearings turn less fast than crankshaft but before closing engine I'd like to have a valid answer about this question. Thanks in advance.
Mike (Venice Italy)

Looks like its available on US eBay:
https://www.ebay.com/itm/265597123788

Dear friend, your suggest is WRONG. The bearing on countershaft (clutch side) is number 19 on transmission table and it has code 09262-30022. Type NR dimensions: 30 x 72 x 20 therefore it's completely different. On next time double control..... The doubt remains about gearbox bearings: standard or C3?
Best regards.

Sorry. Your best bet might be a used GT550 transmission.

However thanks for your attempt to help me. Maybe in USA it's easier to find a GT 550 used transmission than in Italy. Then if this transmission has a high mileage like my transmission I didn't solve my problem! it seems quite incredible not to find someone able to answer to my question. For all Suzuki GT models are gearbox bearings standard or C3? I presume these bearings are standard because they have to bring load but not high speed and not heat as for crankshaft. I already prepared a Koyo 6306 NR bearing with pin (30x72x20) standard version......
Ciao Mike