360 trans to motor brace

All right guys I need an expert on this one. I'm puttint a 360 into a formally 6 cyl 1974 duster. I've got a 727 automatic behind the 360. The motor I bought had a brace on the drivers side by the starter that goes from the lower part of the transmission bell housing up to about midway on the engine block. It bolts in solid. I mounted it but it looks like there should be 1 on the passanger side by the oil filter.
Question is do I need this brace on the right side of the engine or is just having 1 enough? I have been told of a guy that left these braces off on his van and it cracked his transmission case.
If I need the brace where do I get 1? I only need the passanger side.

Thanks
Old School