you want to install the 4x4 aluminium x-member onto a 205 engined block 2wd sierra?

it should work if you have the complete engine mounts from the 4x4 x-member and block.

don't know if the steering rack is different, or the locating points for the Track Control Arms (I guess that they are as the 4x4 has different hubs to the 2wd.