You can buy longtubes with high-flow cats. I’m not sure on price for the budget headers with their y-pipe and cats but others here have gone that route. I went with American Racing longtubes with cats but they’re speedy. ( My Denali doesn’t use a y-pipe) There are other options though, you should explore. And depending on how old your cats are, they might need replacing soon anyway. Sure would be a shame to go to the expense of shorty headers and then have to replace your cats in a year or 2 and have spent the same as longtubes and new cats up front. Might have to save for awhile but that would be worth it.