Brown & Gammons list the same part numbers for MGB and MGA Twin Cam for the bearings, bearing spacer, shims, retaining washer and nut. In the SPL for Twin Cam the numbers for bearings, spacer and nut are different, but may have been updated after the book was published.

Item   B&G MGB:           B&G Twin Cam:   Twin Cam SPL:   
22  1A4742  LOCATING WASHER    (ditto)   (ditto)
23  53K330  CASTLE NUT         (ditto)   51K330  Nut, bearing retaining
19  88G484  SPACER, bearing    (ditto)   ATB4239 Spacer for bearing
20  GHB102  BEARING, outer     (ditto)   ATB4238 Bearing (outer)
16  GHB105  BEARING, inner     (ditto)   1B4399  Bearing (inner)
21  ATB4240 SHIM (0.003")      (ditto)   (ditto)
21  ATB4241 SHIM (0.005")      (ditto)   (ditto)
21  ATB4242 SHIM (0.010")      (ditto)   (ditto)
21  BTB656  SHIM (0.030")
21  ATB4242K SHIM KIT, 7 piece

On 5/30/2011, Terry Fiona in New Zeland wrote:   "I used the MGB one in my twincam, worked fine. Bought them and the shims from Moss". -- regards Terry