12 Sec. Gen 4 Camaro?
Again, a bone stock LS1 fbody is good for mid to low 13s @ 105+mph. Some have gone high 12s totally stock (manual trans).
Get the car running right first, there is no need for an engine swap, especially if you only want to run 12s.
Car needs to be sorted out, it's missing about ~90hp based on trap speeds. My 3rd gen used to trap around 95mph with 240hp at similar weight with 3.27s. LS1s all made 345-350hp when stock and fresh. Could be that you're not seeing full WOT, could be that the transmission isn't sending full power to the wheels, or it could be that the engine just isn't making the power it should (for any number of the reasons already listed in this thread, not all of which have anything to do with an internal problem.) Further investigation/troubleshooting is needed before any mods IMO.
What should the compression be on each cylinder?
When I pulled the stock 100k mile plugs out of my '02 car they still looked great. Changing them did nothing to improve power or MPG. So, at similar mileage and with a stock engine, unless your car has seen some rough service conditions and/or chronically horrible quality fuel I wouldn't expect to pick up that much lost power from a plug change alone. If they were heavily oil fouled from valve seals or bad rings or something like this (enough to cause such power loss), I'd expect you to have some misfires and rough idle conditions as well. Misfires can also be tracked with a scan tool. If they were excessively carbon fouled from lazy O2s and/or a dirty MAF, you'd probably see some evidence of this with bad MPG and also fuel trim data that's far from optimal in every cell.
You mentioned that the car seems to run great (so I'm assuming shifts great as well?), but trap speed throughout the run suggests that a bunch of power is missing. IMO, the best place to start in that case is with WOT verification (both via TPS and manually, if you can get a helper, including air filter and MAF inspection for excessive dirt/blockage) and fuel pressure/fuel trim data.
I'll report back with my findings. The Best V8 Stories One Small Block at Time
I wouldn't do a compression check before first checking fuel pressure; a comp check is much more work and less likely to be the cause based on the details you've given so far. Verifying true WOT and air filter obstruction is also pretty basic and something that should be looked at before even thinking about touching spark plugs. I do realize I'm sounding like a broken record now and you're obviously not interested in that advice so I'll move on.
Good luck, I do hope you get the problem sorted out. These cars are a lot more fun when they have full power.

I did replace two plugs/wires while I was in there. I also greased the rear suspension like BMR said to do. I was able to get someone to hold the gas peddle down while I checked the throttle body. I verified that it is opening all the way. I guess the trip wasn't a total waste.
I know whereof I speak. Fifteen years ago, I came upon this site from the old school Pontiac world. I knew nothing of electronically controlled engines. Yet step by step, I learned, experimented, and worked.
Start with the basics first and work your way up. End of sermon.
That is a good example of the MAF in a pretty much stock engine bay. Same location and everything, just may look more similar to what you are looking at.
For the record I ran at Richmond dragway with lid, filter and exhaust, no tune running mid 13's ~106 while babying every shift (M6 no drillmod/no adjustable master), over 200k mile original engine, ~150 psi compression all cylinders within 10psi, and on crappy street tires. At the time it should have dipped 12's if I had known about the factory clutch issues, but that's why you read this site for all its worth!
Forget about suspension and all that, your engine isnt performing, and/or possibly your slushbox has issues too. I would recheck compression, new plugs and wires (cheap tr55 and GM red wires are fine), clean the MAF and throttle body, and change trans fluid













