HI, any help here please

the bearings are 6306 but i have seen different statements. Some say use 6306 C3 and others say use 6306 C4

The bearing company i use say ok they are the same size but there is a difference in characteristics.

So which should I use ?

Hi, could do with some help with this.

Barn find 250-1(engine total mess but not ready to run yet) and have replaced dynamo etc for Tezet 12 volt

12v indicator relay, bulbs, instrument bulbs  etc fitted and all ok – even the turn warning / ignition lamp ok. BUT with ignition on the ignition lamp flashes quickly, indicators ok and lamp flashes at indicator speed when indicating.

Is this normal? and did it do this with old regulator gear?