Vmac3

Does it have a a fuel water separator mounted on the frame rail?

Can you spin the fan clutch with the ignition in the off position?

This may help.CH-CL Vmac2 Wiring Diagram.pdf

Clean off the dielectric. This doesn't help. Switch the injector out with a known good one and make sure you have everything clean. Let's keep it simple first. The pumps operate on 2 banks, 1-2-3 (bank one) and 4-5-6 (bank 2). If my memory serves me right, I believe the engine ecu supplies a ground to switch the pump on and off. If you short out an injector all the supply voltage will drain to ground on that bank, and it will kill the engine. I might be wrong. V

Those ceramic lifters were a problem when they switched over. They were failing as much as the steel rollers. Not sure what they changed in the 04-07 engines. Maybe a different finish on the cam, or the introduction of the power leash. With my experience we seen a dramtic decrease of cam failures in those model years. Not saying they never happened, just sayin way fewer failures. The egr stuff kept us busy instead.

I used spring loaded push rods on the exhaust and 417s on the intakes. The hardware in the valve train was updated, and the rockers were plugged off with rivets. This really helped with longevity. It's important to ensure that the spring loaded push rod is adjusted properly.

There were some granite that I switched over from ceramic to steel rollers.

Here is a service bulletin that explains the changes. sb213032.pdf

Totally agree with this. V

No difference between a 350 and a 400, the engine will bolt right in. There may be differences between the cam timing, turbo and injectors. Software will have to be changed as well. Why not rebuild what you have? Or is it not rebuildable? V

Here is a link to Eatons web site that has all the info you are looking for. https://www.eaton.com/us/en-us/catalog/transmissions/fr-series-manual-transmission.specifications.html

Is the check engine light on? Make sure the injection pump connector is good. I believe there is a ground circuit protection relay beside the wiper motor. Remove the hardware and clean the terminals. There is a module behind the passenger side kick panel. Its black in color right beside a big grey module. If it doesn't start try tapping on the black module. See what happens. Sometimes there is water intrusion and does freak the module out. V

Common issue with these ASET engines. Left hand drill bit, penetrating fluid and welding a nut on the broken stud all work. try the easiest method first. You may want to double check the other studs and see if they are coming loose. V

Also a loose output yoke nut can cause this issue as well. The reluctor ring will slip and cause the speedo to drop out. V

Welcome.