A couple of my customers with stock GN's want me to upgrade their card for more street performance to keep up with some of the newer performance cars and keep it rather stock looking and drivable without "hurting" their budget too bad!
The 2 significant upgrades from stock is more air into the engine, and less restriction out for the exhaust.
So a less restrictive intercooler and a 3" downpipe are basic performance upgrades, but current intercooler choices are VERY expensive.
I called Kenny D. about purchasing his intercooler castings, but they are no longer being produced.
We then decided to do our own version of a complete new neck as we wanted it to be less restrictive than with the old version of welding on a casting.
The entire neck was removed and we fabricated a new neck with a cast outlet for less restriction.
These are more expensive to build over just welding on a neck, but even at $275 plus core exchange, and a transition hose, it is a worthwhile basic upgrade.
Oh, I left the one pictured un-painted to make the mods and construction more visible.
When Boost231 walked through my garage the other day he named it the "nick neck" intercooler!