My experience with a manual transmission for street performance, is to put Second gear where you want it, by selection of an appropriate rear gear, then let the rest be whatever,
The reason is this;
>No matter what transmission your streeter has; First gear will nearly always be too low
>And Third gear will always top out at too high a roadspeed.
> But Second is where all the Street action is. So if you can gear the vehicle to run out of power on the downside of the power curve, at or near 60 mph, that will be about as perfect as it gets.
For me, depending on what cam was in it, that was about 5900, in 1.92 Second, with 4.10s, for 60mph.
Which means 30mph was half that, 2950.
That makes a powerband requirement of 2950rpm ..... so I chose a Hi-pressure 360 to punch up the bottom end.
Eventually, I figured out that my engine had a long flat power curve at the top, and she would pull even to 7000 in Second, so I regeared it with 4.88s, and now it was doing 3500@30mph Badaboom.
and with 4.88s, the slowest I could drive it was 3.4mph @550rpm in gear and pullitself.
But, on the hiway, 65 was a tic under 4000, so I bought an overdrive, for 65=3100
Eventually, that got old, and I began to think of a better way.
Eventually I figured out that my car liked a Second Gear of 6.5 to 6.80, expressed as a roadgear.
So, If I was running a 2.66 low box with a 1.92 Second, I needed a rear gear of 3.39, which I rounded to 3.55, for 30= 2550, 65=2870 in 4th
But if I was running the overdrive box with 1.67 Second, I needed a rear gear of 3.91s for 30=2440, 65=2310 in 4th. I ran this for a few years.
But, like you, eventually iI found the 3.09 x 3.91= 12.08 first roadgear to be too deep. I had a shed full of pumpkins so I began to look for a sweet low gear ratio, and ended up at about 11/1 ..So then I had the first two gears sorted, at 11 and 6.8, which only come in one Mopar combo, namely, the Commando, and 3.55s. So I called Passon Performance, who supplied a real nice gearset. and to that I added the GVod, so
Today, and since 2004, my ratios are .......... 3.09-1.93-1.40-1.00-.78od
With the 3.55s, the roadgears are ............... 10.97-6.82-4.97-3.55-2.77
Compare the closest AX15, with 2.94s at ... 11.26-6.85-4.23-2.94-2.32
Well looky-looky, the first three gears line up pretty good; but to pull a 2.32 for 65=1880, with any kind of fuel economy, is gonna take a pretty small cam, but hang on; in Direct, 65=2380, which would be perfect for a 340., leaving 2.32gear for 2380=82 mph which is looking pretty good.
In one of my combos, I ran 65=2240 in GVoverdrive, 82= 2010 in Second over. My small-cammed 367Hi-pressure, got fabulous fuel-economy.
Now, as to your standard box A833, the ratios are 2.66-1.92-1.40-1.00
And I'll bet you are gonna need at least 3.55s to get off the line half decent, so lets see how that compares. I get ... 9.44-6.82-4.97-3.55
and 65= 2870. I was no fan of that, so I cruised at 56= 2480, until I got the GVod, when 65=2240. Now I'm a happy happy guy.
But I'll tell ya, a nice hi-compression 318 would love that AX15 with 2.94s ; 11.26-6.85-4.23-2.94-2.32, 65=1880.