so i believe i am going to just go the route of bored tb & intake mani plenum match rather than the 09' mani swap (don't wanna risk needing more costly parts/more work to make it fit a 99'). my question is does anyone know if using type s lower runners will add any significant gain since i'm not using a type s or larger tb? & would i need to port match them to the upper (stock 99' IM)?

 

You should port the shit out of everything, I wanted to do the 09 Manifold Swap but It might have some gains but not enough to justify the hassle since I will be rolling the same TB.. So I´m in your boat right now though:

I have TL-S Ported Runners, Ported Heads and Ported Manifold! even the TB Intake Area was shaved a little.. I did this all by myself and did notice a difference it isn't night and day but definitely noticeable.. If you go with TL-S Runner + Manifold swap + TB = Port the Suckers.

 

The runner in the rear are from a clp
The runner in the front is a type s

 

You arent going gain anything by doing that, infact it would be a waste of money. If you are going to do anything get the type-s lower runners and the 09+ intake and a larger TB.

 

The largest gains are had from the larger TB and 09 mani Especially when connected to a 4" intake

 

These do help some too though

 

But I like my Plastic Covers fatty

 

But they help hold the heat in the intake manifold which reduces power, Plus its not like you drive around with the engine exposed or everyone to see. Make your cover fit the 09+

 

09+ manifold looks better than plastic covers

 

^ To some.. I don't like the looks of the wires without the cover (In the TB area) and I got a semi-wire tuck in mine.. soo.. Ill live with my current HP with the ported stuff.