I hear ya! We actually don't know why GM installed the BB transmission crossmember with the LT1 application. We have confirmed that the engine mounts are indeed the SB version, and the crossmember is not the Pontiac version. I wish I could tell you why, but.... that's GM
We have speculated that the BB Xmember was retained under the COPO 9737 package because that package had been applicable to only BB cars for the prior two years, but we agree that it's a stretch and pure speculation.
The deuces actually have the BB shifter rods, but the SB shifter attaching bracket (no 1/2" offset), along with the '69 Camaro Z28 shifter mechanism with a Pontiac GTO bench seat arm. Confused yet?