Interesting question! I really don't see that there would be a significant difference between EFI and carb as far as the camshaft and valvetrain are concerned. But, I'm subscribed.
From the comments I'm seeing, apparently not (and that's a good thing!)
My fear (and assumption) was that the factory Magnum camshafts may be ground with a short duration and wide lobe spacing, thus timed to capture a more accurate air/fuel mixture from the multi-port injectors vs. a longer duration to ingest the less-accurate atomization of fuel traveling through the runners from a carburetor.
Thing is, one of my neighbors - a Mopar ASE Master Tech of 30+ years - and the former owner and self-restorer of 3 Hemi cars and a few others - insists that a Magnum swap-to-carb requires a different cam. Not to say that he hasn't been wrong in the past, but his knowledge is not to be scoffed at (when someone can correctly relate all the necessary requirements of mating the externally-balanced Magnum 5.9 to an A904 off the top of one's head without the need to double-check a single book for reference, I tend to listen. You have to give the man some credit).
And - on the other hand - I must have read every single Magnum w/carb swap success story that exists on FABO, FBBO, and the Jeep forums out there, and not one stocker-to-carb swap that I've seen out there has involved a cam change - and they've all been successes (in fact, the only cam-related issue I can recall has been rtee007's Magnum 5.9 crate - and his cam failed due to a missing lifter dogbone, not due to the fuel delivery choice).
I put a bone stock 5.2 magnum in my work truck 10 years ago, with a m1 dual plane intake and a thermoquad, works great....Only reason the hoods been open is for oil changes. Plenty of power, very good fuel economy.
I believe it. I dare say the Thermoquad may also give you an advantage, as it may emulate the leaner mixture of the MPFI system.
300 HP Magnum crate motor came with a mild cam and M1 dual plane. Instructions say 750 carb and 1 5/8 headers.
Is the purple 300-horse crate cam identical to any other Magnum 5.9 sold off the dealership floor in a Ram/GC?
I have a '00 5.9 in my car topped with a 650 Thunder on top of a RPM. Hooker Super Comps (1-3/4) into Dyno Max VT's. Chrome box ignition. I'm tuning it a slight lean.
It awaits a cam swap in the future, but for now it is a stock 5.9 cam.
Jet it, set it, forget it.
The factory FI keeps the inside of these engines really clean. Cross hatch hairs still visible after 80K. The carb running on the rich side and an ignition not getting all the fuel burnt will shorten engine life.
That has to be the most comforting comment here in this thread, along with replicaracer43's.
I don't intend to run anything larger than a 600cfm Carter AFB/Edelbrock or a Summit M2008, and I'd like to run the '92/93 stock manifolds into a 2" or - at max - a 2.25" exhaust. Nothing earthshattering - I wound up with a pair of Flowmaster 2.5" exit pipes in this deal, and they are just too overwhelming for a stock look - even with turndowns.
All I want is something streetable with a bit more efficiency and internal reliability - which somewhat negates going through the trouble of doing an engine swap for yet another choked-up '60s 318.
-Kurt
