A904 vs A230

IIRC there were two A230s; one for the slanty, and the other for everything else.
The one was 3.08-1.70-1.00; splits of .55-.59 ; this is a wide-ratio
the other was 2.55-1.49-1.00; splits of .58-.67 ; this is a progressive ratio with a wide 1-2, and a tight 2-3.
As a comparison the A833od is 3.09-1.67-1.00-.73 ; with splits of .54-.60-.73
IIRC the slanty had the 904-sized output shaft, while everything else got the 727 sized shaft.
I would not be scared to install a long-tailed A230, with a big mainshaft, on the street.
With a small-cammed Hi-torque 408, any of these would be a fair choice. BUT
if you chose the overdrive, you have to be very very careful about gettuing into od; that gear is very small and IMO fragile cuz even my smog-era 318 has broken one. My 367 has broken two others. So for anyone who wants to argue, I say, "whatever"...
It comes with just 21 teeth, and the engagement load area with the cluster gear is understandably very small.
I have not broken one while already in od, as in accelerating/decelerating. Mine have all broken by shock, while shifting into overdrive and under too much power.
Ima gonna suggest to stay away from those with a 408 cuber. But if you do install one, you might as well line up a spare or two.
BTW
I have built hundreds of those A230s, and IMO, looking at the guts, they are on par with the A833s, and way more robust-looking than any of their predecessors. But I have never owned one (an A230), nor driven one, and know nothing about their metallurgy. But since you have 4 or 5 of them, how about you install one and give us a report.... lol.

As for ratios, the A904 is 2.45-1.45-1.00
But allowing just 60% TM @WOT in the convertor at zero mph, diminishing to 18% in Second and 8% in third;
and with say 3.23s, your road gears are gonna look something like this;
12.70 diminishing to 9.50-5.52-3.49. To compare favorably the A230 would need 3.55s. Then, to get the starter-gear in the ballpark, you would need the 3.08/1.70; and your Roadgears would look like;
.------10.93-6.04-3.55 ; But seeing as how you have a 408 engine, Ima thinking you could get away with the 2.55/1.49 and
--------9.05-5.29-3.55 ; compare these, to
12.70/9.50-5.52-3.49 all at WOT, with the A904.

However, your cruise rpm will change.
With 27" tires, 3.23s and the A904 at say 3% slip, the math says 65=2700
whereas the 3.55s math to 65=2870
Don't hate me but, if you used the A833od you could run 3.73s for roadgears of
.-------------11.52-6.23-3.73-2.72 and 65=2200 compare this to your A904 at
average of 11.10-5.52-3.49 all at WOT, and 65=2700@3% slip. and just for kicks, the Commando with 2.94s
---------------9.08-5.64-4.12-2.94 and 65=2380


Don't forget, when you swap to a manual trans, your slowest roadspeed is directly tied to your idlespeed. Using the same numbers as above, namely 3.23s and 27" tires, an in-gear idle-speed of 800 will get you
6.4mph with a 3.09 low
7.8 with the 2.55 low
So then your parading days are over.
To get to a comfortable 3.5mph, idling at 700, requires a roadgear of 16 to 1
The lowest low in any of these transmissions is 3.09; and 16/3.09=5.18 the rear gear required. You would still need to idle your engine down yet further. You're never gonna get there with 3-series gears.
With 4.10s and a 3.09=12.67, your in-gear idle would have to be 600 to get 3.8mph, and then 65=3320rpm........
Unless you install the A833od,and 4.30s; then 630rpm=3.8 and 65=2540 in .73 overdrive; Now we're talking.
The final roadgears would be;
------------13.29-7.18-4.30-3.14 compared to your A904/3.23s
average 11.10- 5.52-3.49 all at WOT,

Fun with math