Are you willing to crash and possibly hurt yourself and your car if it fails?
A old friend and racer wreck his 1955 Thunderbird badly (He was lucky and only got bruise up badly and sore from the harness for several weeks) with a BB Chevy in C gas years ago when he had a cam gear rubbing against the block when he installed a roller cam with no thrust bearing, it was making metal and I had warned him to take the motor apart to identify and fix the problem, he didn't before he wreck it It spun a rod bearing and broke the rod in the timing lights at LACR at 130+ MPH, that locked the motor up and made him swerve in front of the other car and go off the track into the embankment flipping the car multiple times
Don't take a chance, sell the B crank and buy the correct one now