Alright guys well i have a bolt on G35 Coupe 6mt on 91 Admintuned.
Injen Cold Air Intake
75 mm Throttle Body
Kinetix V+ Manifold
5/16 MD Plenum Spacer
Ebay Test Pipes
Greddy Custom Single Exit Straight Pipe
255 Walbro Fuel Pump
Im just kind of bummed out because I only made 242 whp and 245 wtq and feel like i should be in the 260 hp mark considering my mods. Do y’all think something like this could affect my performance?

Sometimes its very dyno dependent. And also temperature.
I got my tune about 4 1/2 years ago on a nearly 90 degree day and they left my a/c on, best pull was 239/221 but I gained 16 hp and 22 lb-ft torque and my car felt noticeably stronger, which was the goal. Plus at my controlled test road, I was doing 4 mph faster at the end than usual. They said I could bring it back in the winter and they'll make sure the a/c was off so I could get my hero numbers. Of course with my paying for the dyno time.

Whether or not the spacer combined with the intake hurt your power, I don't know. Your torque numbers look really good.

What year is your coupe, 2003-2004 with the regular DE or 2005-2007 with the rev-up DE ?

As for that particular plenum WITH a spacer, I wouldn't do that...

regular De motor 2004

All you need is the spacer.