Mopar Performance Purple Mechanical Camshaft - P4120653AE Cam Card

It's not that the cam needs to be smaller.
What it is, is that the intake valve needs to close sooner, to trap more mixture/pressure at LOW rpm. Once the Rs get up to around 3000, there is LESS TIME for the mixture to turn around and go backwards up the runners where it just came from, so as the rpm rises, the engine traps more pressure, and starts to make some power.
Now, as it happens with Roller cams, the acceleration ramps are quite long, to get those heavy lifters moving without causing the lifters to bleed down, the pushrods to bend or whatever. Once the roller-lifters are moving they can be accelerated faster than flat-tappet hydros, which have a different problem. So the end result is that, the theory goes, that roller lifters will make more power because of the lobe design made possible by the roller.
So in most cases, yes, it takes a smaller cam to get that earlier closing intake valve....... but not always.
Now a [email protected] is already pretty small for most guys, so IMO, you don't want to go any smaller. But a 224 has the power peak in a good place at about 5000rpm, which works very well with 3.55s. So, I mean I had a 223/230/110 Hughes HFT that I really really liked. In fact, more than the 230/237/110 that I replaced it with; and I ran them both at the same pressure (CCP). So there is nothing wrong with a good 224 cam. In your case you just need to get the pressure up a lil.

With the new Scr number of 9.91 this is gonna be even more important. IMO, you will need to run the pressure to the max with iron heads on best pump-gas, with roller-lifters, to get the low-rpm torque you are looking for.
To that end, at 9.91 and for 91 gas, the Wallace spits out an Ica of 60* for 164psi, and the VP is up to 136. This is not a great number but sure beats the current VP, which I no longer recall. 136 with a 3000stall and 3.55s will be fine in your lightweight streeter, which being at least 10% better than the current combo.

Ok remember that number; 60*
Your engine doesn't care how you get that 60*
You can put it on a 114 LSA or a 110 or a 106 or whatever you like. But here's the deal, the wider you go, the smaller the cam will be and the tighter the LSA the bigger you can make it.
Now, you already have a 3000TC, so there is no way I would put it on a 114, nor a 112, there is no reason to widen the powerband. A 110 is the norm. But in your case with a 3000# car, a 3000TC, and 3.55s....and those hi-flo-heads; I see an opportunity here for a 108. Maybe even a 106LSA. Lets run some numbers;
Ok so, I'm liking a SOLID roller lifter at zero lash; for 272/278/106. This, installed at 104(+2), will get you that 60*Ica, and 64* of overlap to boot! This kind of cam is gonna start off pretty good for a 340, and then pick up speed as the Rs climb, then about 4500 it is gonna wham to the finish line, a bit like a pipey 2-stroke dirt bike. I shortened the split to 6* so the dumb thing will make some decent hiway mileage, if you cruise it at 65=3000 with 3 or 4% TC slip, with those 3.55s. You don't need any more than 6* split.
Now; this cam COULD be 272 less say 40* for ramps =[email protected]........ which being 9* BIGGER than the current Comp 223. That is about 1.28 sizes bigger, so your rpm of peak power just went up about 1.28 x 200=260 rpm so from about 5000 to 5260, good deal. That should be good for 20 hp or more ............ With, remember, an INCREASE of low-rpm torque as well.
Most guys will tell you that running a 106LSA with an automatic is a bad idea, because the powerband is too narrow, and the engine will fall off the cam . That is true, if your stall is 2200 like is stock, and you have hiway gears. The 1-2 split in the 904/727 is 1.45/2.45=.592....... meaning, at whatever rpm you outshift, the rpm will drop to .592 or 59.2% .. So if you are just cruising around town with a low power at low rpm combo, like the XR274 in your 9.91Scr 340, and you outshift First into Second at say 3400, the Rs will fall to .592 x 3400=2000, but the TC might be a 2200, so the engine spools up to 2200, but there is no CCP down there so you rightly say the 340 is a dog.
That was like your old combo.( but with a stock stall)
This new solid-lifter combo, is maxing out at 164psi so lots of CCP. And your TC is a 3000; which with your new more powerful bottom end, will be a true 3000. So now, you can outshift first at 3400, and by the math, the Rs should fall to 2000 same as before, but your TC spools up to 3000 where the engine is already eager to go. ............. so no problem.
Would I try a 106LSA?
With a 3000 and 3.55s, Yes I would.
And if that cam had 64* of overlap, oh yes!, I would. (mine has 61* so I know what that runs like.) and
if the .050s were 232/238 (mine is 230/237) , You better believe I would.
And if at the same time as all this is , that engine pulled 164psl CCP, and a VP of 136 as good as it gets; Daymnrights I would try it.
But, I'm also the kindof guy that tries stuff because I am always willing to back up the bus if it doesn't work out. I do all my own work, so it usually only costs me time and gaskets. But I even got that covered using a lot of re-usable stuff.
But Heck-if-I-know if you can even get a cam of this size, or approximately this size.
Remember that number? 60 degrees. This is the smallest ICA that you can run at ZERO-lash for 164psi to run best gas at 91. If you try to run more pressure, your name better be yellowrose, or you will likely need to run an anti-detonant at WOT, in the tricky zone of 2800 to 3600. But you got that partly covered with the 3000stall. And the rest you can probably make work with a slightly delayed PowerTiming. Time will tell.
Run it past your cam-guy and see what he thinks.

Keep in mind that a solid lifter cam will require a way to set the lash. Which may be an added expense for you.

I didn't talk about lift because, I have no idea how much lift your cam-grinder can put on these rather small lobes.

A cam with 232* of intake duration is the biggest hydraulic FLAT tappet I would run on the street, because the advertised is pretty big, (mine is 276/286/110+2) which makes the ICA as late as I am willing to run. (mine is 66*). I run alloy heads and 11/1Scr and my CCA is a tic under 180. With 367 cubes, this is all the performance I can handle. I liked the previous 223/230/110 cam better, and have been waiting since about 2004 for this 230/110 cam to puke, so I can go back to a smaller one ............... but this one just keeps going and going and going..... and I just can't justify throwing away a good cam, lol.


Now, having said all that, if your engine is out and apart, you can get 164 psi by just increasing the Scr to run the XR274......... 10.7 will do it, with a true Ica of 69*.................... but your VP will still lag at 126, due to the long ramps, which, with a 3000TC should not affect you.