Cats after the turbo?
Any particular type to go for? There are more 3.5" cat options than 4", mostly metal matrix ones for diesels. Or would doing a full 4" system be better? Aiming for around 600rwhp on my 5.3L.
3.5": http://www.summitracing.com/parts/MPE-59920/
3.5": http://www.summitracing.com/parts/MPE-60010/
4.0": http://www.summitracing.com/parts/MPE-60011/


