In hindsight you could always make it a point to leave the TB last in modifications. Infact if someone asked what order of mods should I do?? I would recommend in this order:
Tuner (computerized trucks will not be able to take advantage of aftermarket mods without the computer being told to do so. (Simplified) I use i3 because being able to tune the trans is the other have of the battle.
Remove the clutch fan and AC fan. Install the Mopar v6 fan. (Side note) I still want to get pwm control on the 13-18 chassis with a 19-20 fan. I've never been pleased with the vibration the v6 fan can produce. Either we need more antivibration engineered into the installation or that fancy new fan.
Exhaust: Long tubes!!! The hemi heads have excellent flow. We have a dual runner intake manifold stock which the computer adjusts for power. Get those cast manifolds off after you need a gasket and bolt replacement. Use ARP bolts. I can't tell you the loss I feel when I have to do a job again because of bolts. Gaskets I have no opinion on. I haven't had an exhaust leak due to gasket failure. Always bolts. Now Californians I understand your situation with smog etc. Do the SRT manifolds. They are OEM, have heat shields etc and considered mid length. I went with aFe because they put the hiflo cats right behind the header (I like this) the O2 sensors are happy. No extra modifications need. The 3" y-pipe is sweet flowing into a 3.5" mid-pipe before getting to the muffler. This mod has made the most additional power to date. Either my expectations were lowered driving a lifted truck or they just make that much power. My only gripe is 409 SS. I'd prefer 304 but AZ winters aren't too harsh
Muffler: I did a Carven R noise maker
. I'm sure my neighbors hate me but I don't care. It sounds so badass. Up to you if you want to spend money on additional exhaust modifications.
Once the exhaust is opened up you're ready for intake modifications. Assuming your NA like me and more than likely staying all motor you should decide now what intake manifold you're going to keep. The 6.4 truck manifold is an excellent modification. Reason it makes sense here is because of wasting money on the 5.7 CAI orientation. If you decide on the 6.4 manifold you get injectors, rails etc. You will need to either hack-a-cold air intake like me or buy one. You can choose to do a TB while you're in there but it's not a deal breaker if you save your cash.
Cam would be next. Now this is where it gets tricky so bear with me. I HAVE to be able to pass emissions without that Damm CEL light going off unless commanded. I want a full phase cam upgrade. So what does that mean? It means no cam locker because of piston to valve clearance issues. But with aftermarket pistons and enough valve relief built in, it can be done. I need as minimal chop as possible. I can't leave the guy at the DMV without any possibility of passing. Only Harleys get away with that. This is why that 30hp MMX cam is so appealing. I honestly don't want to do more than the drop in cam till the lifters take a ****. I'm trying to limit my spending by wearing out what I have before the Misses will approve upgrades.
Now back to the TB. I was more motivated to get it to work versus anything else. As long as it didn't lose power it was staying on the truck. That's what I told myself anyway. Plus just having hellcat parts that actually work on Ram is cool.
But yeah to answer the question for the drag racers you can definitely spend 400 in tires or suspension that would make a hell of a lot more ET difference than this mod. This is a daily driver don't floor it every where but get much better throttle response modification.