Dude. This is such a crazy build. Kudos to you. Right now, I'm back and forth between doing the same thing with my 89 SWB or building what haztoys calls the 2.6 "steamshovel." Still very much my daily driver, so it's all up in the air, but man, I've got so much of the 4G63 stuff just lying around after the GVR4s left.
Haven't been in this thread in a long time, but checking now, I've got a couple low-buck ideas you might be interested in before you put this sucker on the road.
1. Evo VIII cams. You're already using the Evo ECU, why not pick up a set of OEM "272" cams for $50-200? Head on the VIII flows opposite direction, but there are a couple ways to skin that cat. The cheap route involves cutting a slot into the end of the Evo intake cam and so your CAS will work properly and re-pinning it to accept the stock cam gear. The easier route involves a set of adjustable cam gears, which tend to be machined for either DSM/EVO. $50-$100 and a couple hours could net you some more HP, considering the stock Evo makes, what, 270hp? With that big hog turbo, you're already sitting very pretty, but if it's OEM quality and cheap, well, something to think about.
Link to specs, brief discussion, etc., over on GalantVR4.org. I've since gotten out of the GVR4 game, but still have my Evo VIII ECU (FedSpec, 4-cylinder, 5-speed Eclipse is the same part, just can't do digital boost control, btw) and cams sitting in the garage.
2. Cyclone intake manifold. It's a bi-modal, dual runner intake manifold for the early (read: 1G) 4G63. This is a pretty trick piece of kit. The primary runners are smaller diameter and longer, which typically nets people 40-50ft-lbs midrange. Once you hit preset conditions (triggered/activated via repurposed boost cut and fuel pump solenoids from any turbo DSM), the little wastegate jobber opens the secondary runners as well, flowing within 5% of the 1G intake manifold. Spools a little quicker, and more grunt building that boost to boot.
There are 3 versions, all of which are relatively rare, but pop up from time to time if you keep an eye out. Typically $150-$200 range. Any of them will do, really. I can't find the thread on the Galant board where a fella and I discussed specifics at length, but there's a turbo version, a non-turbo version, and a non-turbo, AMG version.
Keep up the good work. High five, brother.