I just bought a LQ9 from a fellow forum member that has the new TSP 227 heads and was making 480 rwhp through his Kooks 1 3/4" LT's .

He felt the headers were holding him back a little.

I have the exact same Kooks (I think) That are 1 3/4" od. and about 1.5" ID.

I am thinking of ordering the new TSP 1 7/8" headers, my question is my 3" SLP Loud mouth II set up going to hold me back? would it be worth it to spend the money on true duals?

Also what would the difference be between the ORY that I have in there now and putting the 8 year old (but clean low mileage) SLP cats back in?

In short would I really benefit that much from the true duals, and how much would re-installing the SLP cats hurt me?

 

i went from SLP headers, ory, and LM1 to TSP 1 7/8th headers and true duals and it made a huge difference. ran way stronger. so im gonna have to say that there will be a noticeable difference if you went with that exhaust.

 

See I think the LMII is a pretty free setup. Buddy broke 400 hp cam only in an LS1 with a 233/239 114lsa with pacesetters and the LMII

 

I felt a difference going from a 3 inch Y pipe to 3 inch duals on a stock internal motor.