Some motors drop the front bearing too with just a slight tap to get it moving. Two different blocks of the same model & brand motor can also do this.I dont remember how the front in my v-spec came out so no help there but do remember the old GRP ninja was not fun but my buddys GRP ninja just fell out like the rear with a very light tap. If your not gonna run without 2 good bearings & you have to remove the bearing in the os ninja anyway I guess you'll find out how it comes out tonight.I would however use the oven so the whole block gets heated & use the crank to make sure the rear bearing is still seated before cooling.I have wanted a bearing tool but never got around to buying my own & oven has always worked perfectly.Make sure you brake clean the crap out of the block first or the wife will be pissed.BTW I go 350 for 10 min after the oven has pre heated.