Changed !st ignitor in 07 replaced it with a rheem replacement part. Ignitor has failed again. Have had 2 more burn up 3 to 4 seconds after turning red. What should amperage be for ignitor on startup

I wouldn't focus on the amperage. It sounds like the ceramic(black portion) of your ignitor could be touching metal or the new ignitor is not the correct voltage(120v) or resistance (45-90 ohms room temp). Im going on the model # that this unit is prior to 2001. If this is true get an ignitor that works on the same specs as a norton 271.
White rodgers or robertshaw

I appreciate your response but as it turns out 3 ignitors from 2 different companys were defective, they were all 120v 5amp or less parts pulling 8 to 10 amps I finally got factory oem part and I pull 4amps on startup and 3amps after its hot. Had no problem bringing the others back not even an argument from counter sales