is there anything wrong with the stock cats tho? I mean are they really worth replacing them with a set of "higher flowing" cats?

 

Here's mine, i cut 1" off each side of extra material. Ignore the arrow thats where it was leaking but i got that fixed.

 

yeah they are restictive as hell . and will eventually fail possibly causing enough back pressure to hurt other parts of your motor. Why buy a set of headers to increase flow and then stick a cork in them ?

if your set on keeping them , no point in touching the manifolds. Headers arent 100% necessary but will help alot with supporting mods.

EX , a guy i knew had a crew cab srt-10 ram and had 100k into when he was done he had stock manifolds ( not sure on cats) and he wouldnt touch them . He ended up making a ton of power and getting 10's out of it with a big blower and huge shot(300 direct port)on a built motor .If he would have done headers he probably would have dropped another second and gained more than 200 hp.

 

200 hp by doing headers?? wow whats his secret

 

Probably letting that V10 breath

 

having 1000rwhp without them .