My 360 build.

Hey Cley
Aluminum heads and very high compression can help you meet all you goals, with that od trans, and maybe even with those 3.23s........... And more. I know, because I built one.
The OD trans opens up a whole new world for you. And
the high cylinder pressure can make up for at least one cam size. And
When you marry them all together, look-out!
But I gotta tell ya. If you build it right, you will be wanting more, and then the 3.23s will be the first to go. With a .69overdrive ratio, there really is no street gear that you cannot run. I even ran 4.88s and 5.38s for a short time. But don't get carried away,lol, because you will end up with a useless first gear, cuz you just can't hook street tires with street suspension.
Because you have that od, and because the low gear in it is 2.74, it is easy to get enough TM (Torque Multiplication) for nice street launches. This means you can optimize second gear instead, cuz most of that combo's life is gonna be spent in second gear....... am I right? That also means you can optimize the engine for that gear.
With that kindof thinking, it's easy to see that the 292/508 cam is just way off for the combo; cuz the power peak can be as high as 5800, and you might go there once on the way to 65mph..... and your tires are gonna be spinning the entire time. And of course the fuel-economy with that cam is atrocious; YES, even with the overdrive, cuz the engine will be stuck at a very inefficient rpm. I know cuz I built one. So you are right to pull it, IMO.

So think about this;
For a starter gear 9 or 10, to 1, is usually plenty, calling for a 3.55 ratio minimum.
For cruising, 2100 is not too much, calling for about 3.91s to get 65=2100 in loc-up with 28s.
So really any ratio in that range will be sweet. Now lets look at second gear with say 3.91s.
The final drive ratio in 2nd will be 1.54 x 3.91= , so 32mph will be just 2430, pretty sneaky. On the downshift into first, the Rs will jump to 4320, pretty close to peak-torque, and your Duster will jump! Now it's up to the cam to carry you to 60 mph, which is gonna be about 4600 in second. Hmm, that's not gonna be the quickest way there.
Ok lets regroup with the aforementioned 4.30s, and lets put 27s on the back. This will get you 60=5200. Well that's not great either, but it's a compromise. The cruise is now 65=2400 still doable and the starter is 11.78. So IMO, that is as good as it gets.
So now, you just build your engine to be a powerhouse thru the midrange, with a powerpeak at or a little under 5200, BadaBoom!
That is pie.
I see a 223* cam and 190psi, with a tight Q.
Wait, whatabout 32 mph now? With the 4.30s,I see 2630 at zero-slip in second, changing to 4900@5% slip, on the downshift. Well that looks crappy,lol. But wait, is it? Yes and no. With iron heads you might be getting close to the shift-rpm, but aluminums will stretch it out a few hundred, so that 223* cam will go 6000 easy, so you are good to 39mph, then the shift will bring it down to 3370, so that 223* better pull.
This is where that 190psi comes in.
With open chamber iron heads 160 is pushing it with the best pumpgas. And that would make for lazy acceleration from 3370. But the aluminums will burn any old gas at 180. And will still burn pumpgas at 200 (as attested to by members here). Mine burns 87E10 at 185 with no problems. And if you have never had a 360 at 190psi, man you are in for a treat. People tell me it feels like a big block. IDK, I've never had one.
So as it turns out, that trans with it's very wide ratios, NEEDS the 4.30s to get second gear working. So Rumble hit the nail on the head.
Yes, first will be a little short, but hey, you can use the current TC, cuz your engine with a 223cam and 190psi, will be a BRUTE for torque, just what you need for a streeter.
And the icing on the deal is that the 223 cam and cruise rpm, with a good tune, will get you fantastic fuel economy at 190psi. I know, cuz I built one.