I'm just catching up on this thread...
Remember that a smaller turbine wheel doesn't always mean faster spool. A bigger turbine wheel with better geometry and efficiency can out-spool a smaller wheel that's more restrictive. The GTX2867R .82a/r and GTX3067R .63a/r will have little difference in spool time. If one is faster, it's the 30r. Yet, the GTX3067R will have much more potential in mid-high rpm due to the less restrictive hot side.
I also disagree with the bashing of the other brands. I recently witnessed a brand new GTX55R Garrett compressor wheel come apart on the 3rd pass on an Outlaw 10.5 drag car. I also know of another Outlaw 10.5 car running twin Precision turbos for 5 years now with no issues, including 2 class championships. Now I'm not saying that Garrett is bad, just saying that every brand has lemons. These other manufacturers have had issues when they first began due to the learning curve. They've learned and come a long way since those days. Nevertheless, you're gonna find brand loyalty anywhere you go.
Put a Cometic head gasket on it with ARP studs and tighten it to 75-80lbs. Done.
If you want to improve low rpm response with whichever turbo you choose, grab a set of adjustable cam gears and adjust your stock cams down to a 108 or even 106 LSA with a 104 to 102 ICL. This will increase dynamic pressure and response down low. Just be mindful that it will also decrease piston-to-valve clearance, increase overlap (though not enough to cause harm with the stock cams), and increase the liklihood of detonation.
