All car AC compressors are low mount. But a 6.4 can run the same TC as the 5.7 and mount the alternator up top if needed.
Holley has a whole FEAD kit that moves the AC/PS/Alt up to about the middle of the motor. I know of one guy on here that used that and didn't have clearance issues. But it is expensive.
Factory PCM is useless if you go with the Terminator PCM. But the Hotwire kit needs it.
If you run a Hotwire kit, might be worth grabbing the engine harness from the donor. Maybe Hotwire can build you a harness of it and save you a little money? Not sure on that, but might be worth looking into.
Pretty sure the only automatic the Terminator X Max can run is the 42/46RE. And that one requires a separate add-on harness.
All depends on what trans. If you run the 8HP, pretty sure either is a plug and play. No idea on a 545RFE or NAG1.
FYI, Hotwire Auto used to have a tech post on what was required to run an NAG1. Might be worth looking that up if you wanted to run that trans. Should answer a bunch of questions.
VCT and whether it needs to be removed is all based on which cam. And the cam doesn't defeat it, you have to lock the cam phaser. There is a kit you buy with a block you put in the phaser so it can't vary the cam position. Tune is certainly affected so it will need to be changed as well. But an aftermarket cam will almost certainly make a tune required so it would kind of be find automatically at that point.
MDS is also mechanical and electronic, but not plugging in the solenoids would defeat it. No idea if it would cause issues with the way the car runs if MDS isn't turned off in the tune, though. Personally, I would remove all the MDS stuff (block-off plugs and different lifters) and remove it from the tune.
The SRV (not SRT) function is pretty cool, I want to save it on my build. But the solenoid hits the firewall if the motor is in the stock location and the best intake option is the 6.4 intake which can be more expensive and doesn't work with a high mount alt. Either way, it also affect the tune so it probably needs to be removed from the tune at least.
The out of the box TTI mounts require a block off plate. But at least one guy modified a QA1 k-frame and moved the mount back on the TTI bracket and cleared up a bunch of room.
[URL]https://www.forabodiesonly.com...her-son-project.364889/page-6#post-1971925482[/URL]
As to which is better, kind of up to the person. I don't like the clutter, but it might make adding a true oil cooler easier. Six of one, half a dozen of the other.
Couple of thoughts.
I plan to run Holley's motor mounts as they move the motor forward and are supposed to allow for the low mount compressor on VCT motors. But relocating the motor means the trans crossmember and anything connected to the trans will need mods. I have a T56 Magnum to plug in at the same time so it doesn't mean much since I have to rebuild the mount and crossmember anyways. This also clears up room for the SRV solenoid on the back of the 6.4 intake or the cooler manifold on an HC supercharger.
I hate moving the motor forward 1.75", but I'm not building a 10/10th race car and the motor is still significantly rearward of the front suspension centerline when compared to a new Challenger. Everything is a compromise and in this case it is the compromise that saves me from running a $3K+ Holley FEAD kit.