I've talked to a couple guys that are making decent power out of the LT you basically get to a point where you convert to port injection while in boost. Even with larger cam and lt4 pump (supercharged engine di pump) unfortunately there's no good way to keep DI and run a 4l80e trans or really a manual 4 speed for that matter but I'll cross that road later. im still way up in the air on what engine it's gunna have but as you seen I have ALOT of work between now and then.Wow a 55 nice!!
If you go with an Lt style engine you can change the cam on the fuel pump to increase the flow and pressure.
They make the kits for the V8 version don't see why it wouldn't work for the V6