SM465 Crossmember

[1972GMC2500]

I have a 1972 GMC 2500 that I am putting an LS motor and 4l60e in. I just pulled the 402 and Muncie SM465 out. The crossmember for the SM465 is under the bellhousing instead of at the tail of the tranny. Also, the crossmember is riveted in instead of bolted in. My question is if I can leave the crossmember in to help keep that strength in the chassis. Has anyone done an LS swap and left it in? I don't want to wait until I'm putting the motor in to decide which way to go. It looks like it is going to be a pain getting it out.