Just to follow up on this, Ehrenburg is doing a G3 swaps series in two A-Bodies (the second one being the Green Brick) in Mopar Action. He is using the Holley mounts for at least the first one and in the most recent article he did have to clearance the fan shroud due to interference with the water pump or something. So you are right that moving the motor forward causes some challenges with the FEAD clearances.
Seems like six of one, half dozen of the other. My brother is doing a 6.4 swap into a Demon and had to remove the bottom stud for the wiper motor to get his Edelbrock intake to bolt down. And there was no way he was going to be able to run the SRV solenoid on the stock 6.4 intake he tried. Add that the Holley mounts mean you can run the stock FEAD and low mount AC compressor if you want. So making some things work means others are tight.
To be clear, in wasn't like Ehrenburg couldn't get things to fit, only that it took some minor trimming. Now, he used a LX/LC radiator and fan setup which could be slimmer than some might want to run which means a thick 8 core ( :D ) radiator might not work.
