Living with a 2.21....

Don't be thinking a 2-chunk system. I tried that and it got old in a hurry. It's about an hour and a quarter each time.
Don't be thinking tall tire short tire either, the range is too small. I tried that too. The range is about 10%, but it's the wrong way for traction.
The other choice is a winters QC . I was thinking about it but the GVOD was an easy G cheaper.
IMO, the best idea is to boost the power at lower rpms, and be happy with an intermediate gear like a 3.23/3.55
There is a program for performance WITH economy.
................... First for economy..............Second for performance
compression ..lots...........................................lots
overlap; .......as little as possible,<40*............. lots; >60
extraction...... lots,like >120* ........................ <110*,mostly don't care
TC.................low stall/loc-up......................... hi stall
cruise revs......low ........................................ don't care
Starter gear.... whatever ................................ >10,<13
weight........... light ....................................... light
aerodrag ....... low ........................................ under 65mph don't care

So check out the commons; lots of compression,and light weight.

But for you,IMO, the A833od is a a reasonable solution , but I would ditch that cam if I did that.
I might run it with 3.23s for 75=2150rpm, and a starter = 9.98,and 32mph=2150 in second; and that's where your 268* cam hits a wall. With just 130 psi and VP of just 100;there is no performance with those numbers. To run that 3+1 manual trans with it's very wide 1-2 split(.54) the engine needs to make a ton of torque below 3600 where most of your running is gonna be. That 3.23x1.67=5.39 second gear will make 60=about 4000rpm, so you need a power peak just under that, say 3800.Well that is not gonna be real impressive. You would need more cubes to liven that up; or supercharging.
But the next rear gear 3.55 is plus 9.9%. That would certainly liven up the zero to 60 mph. Lets work it out;
With 3.55s now 75=2400, the starter gear is 10.97 awesome, and 32mph is now 2360. Ok you are still gonna have to dump that cam. And 60mph in second will be 4420rpm so that's looking up. This cam should peak at 4200ish for low ET. That's pretty close to the stocker, maybe plus one size.
Now you say you have a roller motor, but the cam you listed is a FTH.
So I'm guessing you have a 9.2 Scr engine.
If that's true and exact, then I would run a solid FTH, at 248/256/110+2
For about 207/214 [email protected]. That is 11* less than the current 218/or about a size and a half. or 20/25hp or so.
Here's the thing about this smaller cam; The cylinder pressure pops up to near 160, which is plus 30psi over your currentcombo. And the VP pops up to 130, also plus 30 numbers, or plus 30%; this is like a turbo on the bottom. So it will have way more power below about 3000/3500 than the current cam.Your current cam peaks in first gear at around 5000rpm/63mpg. Second gear is outta sight at 113mph. Now this smaller cam will peak at a lesser power number, but; on it's way to 60mph,it will pass thru the power peak twice, once at about 4400=32mph and the second time at 4400=60mph. So even tho it gives up 20/25hp, it will be quicker from zero to 60 mph; less is more in this case.
The 248* cam, as a 110LSA has 32* of overlap,compared to the 48 of your current cam. It has 128* of compression, compared to the 120 of your current cam. It has 120* of extraction compared to the 112 of your current cam. It makes 160psi, compared to your current 130. And the VP is 30% better with the smaller cam. The smaller cam is better for your combo in every way...except it sacrifices absolute power, to get all those pluses.
So finally we come to economy.
You said you were making 19.2mpgs with your current cam, idling along at about 75mph=2060rpm.
Now you will be running at 75=2400, or plus 16.5%, so that could be a loss of mpgs of about; 16.5/2 =8.25% or less 1.56mpgs. But with the smaller cam, and waaay more efficient 160psi, and extra 8* extraction, and manual trans, I'm pretty sure those factors will increase your mpgs back to the former 19.2, and possibly 2mpgs beyond. now you are up to 21mpgs
So then as a two-gear, 0to60, car with a 10.97 starter gear, I wouldn't be afraid to tighten up the LSA to 108 or even 106.
Ok so; the 108LSA will pop the pressure up to 162 and VP back to the stock number of 133. The overlap increases to 36* and both compression and extraction are increases another 2 degrees. On the hiway your mpgs might increase a fraction, and around town she might use a tad more gas. The powerpeak will go up a few rpm maybe 50, but again the bottom-end is back to stock........ but you now have TM of 10.97, versus 6.06 plus TC as a stocker. So your off-the-line would be vastly superior now.
The 106LSA cam would increase the powerpeak perhaps another 50rpm, the VP would pop up to 136, and the pressure is maxed out for iron heads and pumpgas, at 165psi. On the hiway you could theoretically run 87 gas, but at max load it will want best guess.
'Course if you were willing to go to a 106LSA, solid, then you might as well get a 252/260/106+2... which drops the pressure back to 162@133VP..... and now you are up to a net211/[email protected], just one cam size down from the current cam, with no loss in low-rpm performance, compared to the stock 318; and the potential to make a bit more hi-way mpgs and a lot more city mpgs compared to the current engine and combo,and of course a much stronger 2-gear,0 to 60,ET.
BTW, this is about the only way to optimally use that A833 box. The more cam you run with her, the worse the 1-2 split Feels. The more torque your engine makes, the sooner you can hit second gear.
Above is an example of how to take a 318 with a 268 cam,and a weak-azz 100VP, and boost the VP back to stock (130plus) yet move the power-peak back to within about a half cam-size of the 268. That's power with economy, and we never touched the Scr.

Ok so that's all I got. Pretty UN conventional
Thanks for the blessing, and right back atcha.