I have an '06 G35 Coupe 5AT, pretty much finished my exhaust, and put a Motordyne 5/16 copper iso thermal plenum spacer kit on as well. Next looking to purchase a NWP 75mm throttle body to go along with a 3.5" Admin Tuning intake. Just curious if adding a new manifold to this combo is worth it? I know there's a mandatory tune needed to run the intake, so if there is a better manifold to run for my 5AT alongside this combo, id like to have it all installed before tuning. Thanks!

 

Since you already have the spacer, replacing the manifold isn't going to do much.