That's what I was going to post. LOL
It's square tubing instead of stamped piece like the factory.
Should be stiffer. Now the way I took from the article, if
your C4 was manufactured after the factory started using
the cross brace on the rag top, the coupe should already have
the holes there.... Plus you have to mount the fuel filter up a little
higher on non cross brace year models.

If the poster doesn't have a year model with the holes there, he would
be advised to get that issue of Corvette Fever... The pics would be very
helpful.