[RyzRT]

I am thinking of the followings for the power mods.

• cat back exhaust
• long tube headers
• CAI
• 85mm T/B

Cat back exhaust is a good idea but it is just noise without higher flowing cats.

Long Tube headers it seems is old school mentality many live by today claiming it is the only high power solution, even though they are extremely difficult to mount, force additional changes to use them, and some hang too low below the cars frame.

Many say you just cannot get the HP otherwise but how can that be as the Scat Pack and the Hellcat use modified short headers and build the HP they put out.

I suggest short headers designed for the 5.7 as they are a + or - 15 HP over the slab of cast iron bacon on the stock 5.7. Then add a set of High Flow Cats connecting to a good Cat Back Exhaust.

A CAI is good as long as it is not doing the complete opposite and costing you performance you already had.

85mm T/B is snake oil on the naturally aspirated 5.7 maybe go though thefastman and have your 80mm tapered to 82mm, he knows what he is doing.

Addressing the 6.4 swap, there is nothing wrong what so ever with the stock 5.7 intake manifold. Many that have swapped it really have not come back posting any serious results so why do it. Some ran into problems even doing it getting the runners to function properly, but when that happens they don't seem to want to share that happening.

Try to keep in mind it was not designed for the 5.7 engine but to give the 6.4 back the performance it lost with its Top End design, back on the bottom end and mid range, just because you can do something does not mean you should.

6.4L HEMI has an active dual-runner-length intake manifold for low to mid-range engine speeds without compromising the higher-end power of SRT V8s.

https://dustrunnersauto.com/dodge-hemi-6-4l/

My advice is research, research, research, before you spend the money, because if you are after more power and you install something that actually hurts your power, it is a serious gut punch after you have spent the money to change it out to what actually works.