Yeah, I've been reading up and they seem harder to mod/tune, or at least less options for it. I had also read about the EFI to correct the gas gauge.

I don't know, maybe I'll just put in a new intake, and see how bad the manifolds are (had a stainless p-log on the 2000 GTP which was much more open than the stock) and let it breath more.

Without the u-bend, is there a great need for a downpipe upgrade?

I figure I am set back at least a year on where I was before with mods just to get through the basic airflow stuff and other maintenance that will need to be done once I start driving the car and find its quirks... Plus it is winter and REALLY cold right now. Don't want to be freezing my butt off working on a car that drives just fine. :-)