Just to add;
IMO, the 5.9M is the engine I would chose, but, if you intend to stick with a manual trans, then;
because it has already a 9.2 or so Compression ratio, you are limited in how SMALL a cam you can run, before the high cylinder pressure runs you into detonation. And
You are limited in how BIG a cam you can run, before the bottom-end goes soft.
Actually, with the engine stock, there is a very specific small-range of intake valve closing angles, that will get you optimum pressure to run the grade of gas you choose. You can run less pressure. but running more can get you into trouble.
Assuming the 5.9M is at a true 9.2Scr, and that your local elevation is 500ft;
Your optimum pressures are about;
165 with 91 grade gas, 160 with 89 grade and 155 with 87.
to run 155, your Ica needs to be about 57*
to run 160, your Ica needs to be ~53*
to run 165, your Ica needs to be ~48*
As you can see, the later the intake valve closes, the lower goes the pressure
the Big Mutha Thumpr SBM has an Ica of ~72* way off the chart. and so the pressure is predicted to be 132psi; extremely low. Now remember, with a clutch, the tires are married to the engine; you cannot be at 2800 and zero mph unless you are slipping the clutch. That means a soft bottom-end is a big fat disappointment.
With that 3+1 transmission, you will have to rev First gear to 4400, to drop into Second at 2400, to find some torque to continue accelerating NORMALLY, never mind briskly. 4400 in First with 235/75-15s and 3.23s is 38mph. Can you see the problem there? Do you want to do that nearly every single time you take off in traffic?
Typically I shift my 367 at no more than 2800 when just tooling around. My manual trans has ratios of
3.09-1.92-1.40-1.00-.78od, and I have 3.55s with 27" tall tires; so 2800 in First is 20mph. On the shift into Second, the rpm drops to 1740. But my 367 has so much torque that if I mash the gas, the tires will spin. I built this combo to do that. The current cam has an Ica of 66*. The previous was 61* and it had even more low-end grunt. Neither of these cams has a noticible idle-lope at 700/750 rpm. These are small cams that make tremendous low-rpm torque, when coupled with optimum pressures, tremendous for a 360, lol.
To continue;
The operating range of the Big-M cam is listed as 2500 to 6200. The .050s of this cam are 243/257/107+5; no, 257* is not a typo; this is a very big cam. If it's your first time in this arena, I can tell you that it will NOT be an easy tune for you. The lifts are advertised at .568/.554 at 1.6 rocker ratio, so that will not even work on the stock heads.
There is not a snowball's chance in hell that I would run that Big Mutha in a 360, period. Not street/not race.
BTW
the pressure with an Ica of 72*, in a 9.2Scr/5.9Magnum, is predicted to be just 132psi as stated above. Car for car, at low rpms, this will feel like a lo-compression and tired, 273 2bbl. By 1800 it's picking up. By 2400 it should be out of reversion. The power might start around 4000 and peak around 5500, and with Magnum heads, your shift-rpm might be at around 5800, but you'll have to get your guides modified to run the lifts.
5800 in first with 3.23s and a 90.7" roll-out, is 50mph. In Second it is 92mph. And you'll never hit 5800 in Third/Direct on account of it's 154 mph.
So it should be obvious to you by now, that if nothing else, the 3.23s are ALL wrong. And so is the cam.
Ok so I can hear the gears in your head working; What is the right rear gear to run with that Big-M cam? Well it really doesn't matter because it's the combination that is all wrong. Starting with the 3+1 transmission. The gears are just too far apart for a hi-rpm cam. It doesn't matter what rear gear you run, THAT wide-ratio trans is still the biggest problem.
The ratios are 3.09-1.67-1.00-.73od. and
the splits are; .54.-60-.73, but you have to be gentle going into od else you will blow it up. What these numbers mean is that at the 1-2 shift, the Rs will fall to 54% of what you outshifted at. And at the 2-3 shift, the Rs will fall to 60%. This is not a big deal with a stock slanty because shifting at 3200 say, the Rs will fall to 1730 and 1920, and the slanty has enough power at those rpms because it is a low-rpm engine running a low-rpm camshaft.
Not so with a Big-M cam in a 5.9M
The point I'm leading up to is that, in the end, the Big-M camshaft will cost you a whole different transmission, and possibly a whole different rear end, and for sure an engine rebuild to a higher Scr; not to forget that the heads will have to be modified to accept the hi-lift specs.
IMO, I would leave that cam on the shelf.
Instead;
I would figure out what transmission and gears you currently have, what tires you want to run, and your budget; and then either select parts to work with what you have, or get a bigger budget.