I don't know how a cross pipe affects a V-10 but I do have some experience with V-8's. Here's a link explaining a V-8 cross pipe.
Cross Over Exhaust Pipe Explained... - MustangForums.com
I suggest that you do a dyno run before and after your work, then you'll know what you actually did. There's a lot more to an exhaust than getting the exhaust outside the engine bay!
There's some temperature methods that can help you determine exactly where the cross pipe should go for highest performance - I've never done it but you use temperature sensitive paint and at a certain location is the best place to install a cross pipe. I raced in a series a few years ago that didn't allow cross pipes because they wanted to keep the horsepower down.
For sure it'll be a fun project!
In 1995 I toured the Ferrari factory and I made friends with the guy that owns TubiStyle exhaust (Fausto), just down the road from the factory. He made exhausts for endurance racing cars (LeMans), off shore boats, all Ferrari's and even some Ferrari F1 cars. He had no flow bench and no dyno. I asked how he knew his exhaust made more power. He said he just knew..... No science at all. No emperical information - just his opinion. It was sound that he was selling, not power. Pointless in my opinion.
Greg