Outer Limits 4x4 Board

I have a pair of RB30 diff centers which i would like to use in my TB42 patrol. the RB30 rear pinion flange is te same OD as the TB42 Front .
Can i use the RB30 rear flange on a front center. I have a spare big flange for the rear to suit TB43 running gear.

I have the rb30 diffs behind a 4.2 diesel, I just unbolted the the pinions fron the three ltr and bolted the 4.2 ones on. I have to run 44's to bring the gearing back to standard.
Cheers...........Vic