Riva and R&D each have excellent mods for the RXP. I'm interested to know if the mods compliment eachother and is it ok to mix and match products from each manufacturer. In particular, I like the R&D pump intake grate and the Riva engine intake/filter kit.

Any problems mixing and matching mods from each company?

Typically you shouldn't have a problem mixing and matching. However, you can't expect to get the exact results claimed by either manufacturer. It's also harder to troubleshoot when experiencing problems. If you were to call our tech rep concerning a problem and it's determined that the problem is caused by another companies product we can't be expected to diagnose or resolve the problem for you. And vice-versa.

On reputation alone, I'd go with Riva stuff.