B/RB use the same TC and bell on the tranz
the wider part of a B/RB should be the heads not the tranz bell or starter location
they use the same tranz and starter and TC
well thats what I got from a 383 and a 440 in an A-body..wider at the VC not the block and tranz
guess it depaends on who is bending pipes and who has been
out at lunch and bending pipes at the header factory
I have had the same part # and 2 diff header pipe shapes bends...one size to fit all kinda thing they did list them to fit 2x and 4x truck though they did not fit the 2x truck on the drive side