For comparison: Gear carrier (main axle housing) gasket.
Live Axle
38320 GASKET-GEAR CARRIER
LIVE AXLE H145 38320-18010 GASKET-GEAR CARRIER $1.70 USD H150 38320-H5000 GASKET-gear carrier 38320-H5001 Gasket-carrier $4.43 USD H165 38320-04110 GASKET-GEAR CARRIER H165 38320-N5000AS Gasket-carrier $4.27 USD 38320-N5000 38320-N5001 H190 38320-B3002 Gasket-cover $4.13 USD 38320-B3000 GASKET-GEAR CARRIER 38320-25670 GASKET-GEAR CARRIER (10) 38320-25660 GASKET-GEAR CARRIER (10) LIVE AXLE - SALISBURY TYPE CA200 38353-Y0801 38353-Y0800 38353-Y0812 ?
8-bolt circle H145 H150
8-bolt circle/straight sides CA200
IRS
NOTE: Gaskets for IRS diff are used by some RWD diffs, so there are two parts codes:
38320 GASKET-GEAR CARRIER (rear final drive) 38520 GASKET-GEAR CARRIER (front final drive)
NOTE: all have shape of a Squared-Off Circle R200 8-BOLT Width: wide R180 8-BOLT Width: medium R160 8-BOLT Width: narrow R145 8-BOLT Width: medium
R145 38320-01G02 Gasket Gear Carrier $28 USD 38320-01G03 38320-01G00 * reportedly interchanges with R180 gasket R160 38353-21000 (R160 from 510) 38320-N1901 R180 38353-U3000 R180 $5 USD 38320-U3011 38353-78500 * USA.S130+910+M10+M11 * JDM.M10+M11+B12+U12+910+U12+P10+C31+F30+C31+N13+R30+S12 R200 38353-N3100 R200 $5 USD 38320-N3111 * USD.S12+S130+Z31
999MP-A7007P K11 [w/fluid coupling] [split gaskets] *C8320-00330 $22 Silicon Gasket
38320-01G03 38320-01G02 Gasket Gear Carrier $28 USD 38320-01G00 * R145 and R200? * JDM.N14,N15,B13,B14,B15,C22,C23,D21,D22,F23,E24,M12,VE24,WE24 G10,JU30,U30,N30,RB14, R20,R30,R33,S14,W11,W30,A31,C33,C34, R20,U13,WD21 * USA D21,D22 (front diff, four-cylinder models)
38354-41W00 720 front (R200?)