A500-42RH swap question
It's a very stout piece. USCarTool says it is built to compensate for the fact you are cutting out the top. Indicating no need to weld in a top hoop.
I went ahead anyway.
There still seemed to be a drivers side clearance issue though, & pushed the tail of the trans at an angle to the pass. I ended up cutting it & drilling new holes to get engine and trans straight.