5.9 Magnum crate motor

I have a 5.9 crate motor that I picked up for my Dart. It was in a customer's 71 340 Cuda and a found a 71 340 and swapped out the motors. He didn't want the 5.9 and I got it for 1000.00.
I bet it doesn't have 200-300 miles on it and thought it was a real good deal beings it included the flywheel, oil pan and intake. I did drive the car with the 5.9 and it ran real good. I'm thinking it is the 300hp version. Ran like 300hp and has the dual plane intake. I would like to get it up close to 400hp. The book says it has a .385/.401 life cam. The 380hp version has a .501/.513 cam but having a hard time finding that MP cam. I going with a 4-spd and 3.55 gears. Will be a street car and will drive on cross country trips. May use 3.23 gears on the trips. Going to run a Holley for now but would like to go to EFI someday. I have a few questions.

What would be a good roller cam? Would like to keep the lifters and valve springs which are the same as the 380hp version.

What is the compression ratio?

What is the rocker ratio?

What is the problem with using a/c on this motor?

What other tricks could I do while it is on the stand?

Many Thanks

Pretty much the 380 hp version was a cam and intake change.

Hughes engines has a good selection of cams and a regrind is cheap, assuming you have a good core to return.

Thanks. I was looking at Hughes and they say not for EFI. Wonder why?

When I ordered my Hughes roller cam for my magnum engine he asked if it was an efi engine. Told him it was for a carb app and I might put a FAST efi on it later and he found a cam that worked for me. I think it has to do if it is computer controlled like for the Rams and Dakotas.

They have a lot of EFI cams, but only a couple with play with a factory computer without a programmer or flash. Call them and talk with Dave. He can help you out. I have one of the smaller EFI cams in my 5.9 in my Dodge Ram 1500 van. Gave up nothing on the lower end, but will now pull past 5,000 rpm. Money well spent.

Ok I follow ya. Yes it would be a Fast or the like throttle body injection.

The cams are different for efi and carb. Carb cam is longer for the mechanical fuel pump, efi cam has no provision for the cam eccentric. 300&380 will work with fi or carb. Went through this myself, ended up buying the RT and 501 cams off e-bay. I wanted the mech fuel pump. Had to change timing cover too.

The crate motor already has the mechanical fuel pump so good there.
I'll get dave at Hughes a call.

Anyone know the compression ratio?

Rocker ratio is 1.6.

You'll want to keep the lift under 0.525", so long as you have the R/T springs (these are the straight ones, not the beehive type on a stock 360).

Lunati can make you really any cam you want. I would get something under 230 degree duration at .050 for a street car.

My 340 has a 227/231 .530/.530 hydraulic roller on a 110 LSA with edelbrock heads and 9.7:1 CR and it works well with the 4-speed and 3.23's. Engine made 470hp at 6000 rpm with a 750 dp. It now has SMPI (MS3/Edelbrock Super Victor EFI, which works excellent).