Alternative to a dakota bellhousing

In post #2, I showed how the Ax15 offers absolutely no advantage in the first four gears, over a Mopar 4-speed. The one and only advantage is the 5th overdrive gear. By positioning second gear where you need it, with any of these manual transmissions, you will not be "rowing" gears.

In fact, the automatic is/can be a better choice. You may be conditioned to thinking that it is "just" a 3-speed, but are you aware that the Convertor operates as a stand-alone 2-speed fully automatic and continuously varying transmission, with a ratio range of about 1.8 to 1.1 which is a full gear split of .61..
Thus the 3-speed TorqueFlite with the convertor, together, operate as a 4-speed automatic. If the auto also has a Loc-up feature, that adds about a half a gear, so now it is a 4.5-speed.
The Convertor has, internally, a Hydraulic multiplier, that automatically varies it's "gear ratio" in response to input torque and the resistance of the load behind it.
Max resistance occurs at zero Mph, with the throttle at WOT, so this is when the multiplier is greatest.
Minimum resistance also occurs at zero-mph, but now with the throttle at idle. So in between WOT and idle, principally, you control the multiplier with the throttle.
Additionally, the Multiplier is continuously falling with roadspeed, until the car starts bucking the atmosphere which resists increasing speed.

Lemmee show you how this works.
Again, lets gear it for a an optimum Second gear ratio, which I will chose for it's characteristic of running out of rpm at 60Mph. I will target about 60=5200;
At WOT, with the A904 this will require 3.73s
I will use a 1.8 multiplier off the line, and average the multipliers as we go along.
I will select 1.4 in first gear, 1.3 in second,and 1.2 in third for speeds below 85 mph.
First; the A904 ratios are; 2.45-1.45-1.00
Next; off the line will be 3.73 x2.45 x1.8 =16.45
thru the rest of First; 3.73 x2.45 x1.4=12.80
Second will be 3.73 x1.45 x1.3=7.03
Third will be 3.73 x1.00 x1.2=4.78
Relaxing the throttle at 65 to 85 mph will get you about 3.73 x1.00 x1.1=4.10,
and in loc-up 3.73 x1.0=3.73
I will make top of Second gear in bold, and the rear gears in bold
So lets line them up sequentially;
(16.45 diminishing to 12.80)-7.03-(4.78diminishing to 4.1) and 3.73(in loc-up); looks like
16.45/12.80-7.03-4.78/4.10-3.73; for 60=4900@20% slip
I count 6 useful gears, the first four for WOT operation. Compare that to
........... 10.97-6.82-4.97-3.55, ; the Commando, for 60=5140
.......... 11.26-6.85-4.23-2.94-2.32; the AX-15 for 60=5170
16.45/12.80-7.03-4.78/4.10 -(3.73s in lup); for 60=4900(20%slip)
Notice that the A904 adds one ratio at the very bottom, which catapults your car into 12.80. Again the only thing missing is overdrive.
But hang on; 16.45 is pretty steep on the bottom; we could give say half a gear away there to reduce the cruise rpm, and then install a loc-up, for another half a gear. Lets try 3.23s. The new road gears, figured the same as before, are;
14.24/11.08-6.09-3.88/3.55-3.23, second gear still in bold; compared to
.........11.26-6.85-4.23-2.94-2.32 the AX-15 with 2.94s
But hang on, we have lost optimum second gear. So then we might as well equalize first gears between the AX15 and the A904. so let's target that 12.37 starter, and with 2.94s, I get
12.96/10.08-5.54-3.53/3.23-2.94.......... compared to
...,.....11.26-6.85-4.23-2.94-232 the AX-15 with 2.94s

Yeah I admit that the AX-15 with 2.94s might be a hair quicker to 65mph. But I doubt it will be quicker to 40, But you can adjust that with stall....... if you have a loc-up.. With a loc-up, there is no good reason to run a 2000/2200. And that opens the door to say a 2800, which is a game-changer.And in Lup, the fuel consumption difference will be negligible.

In conclusion;
on the street; the right gear to run with the AX-15 is the 2.94, and at WOT, you will shift it one time in the zero to 60 contest, ending at 5170 (top of second) with 26.75 tires.. And it will cruise at 65=1900, Whereas with the A904(2.94s), you will hit 60mph (WOT) at 4200, and cruise at 65= 2400 in loc-up/ say 2520@5% slip.

Lemmee show you one other thing;
say your 318 manages to pump out 280 ftlbs at whatever rpm. Let's see what that will look like to the rear axles. First with Ax-15(2.94s); then the A904(2.94s)
....3153 ..1918-1184 .......823-650
3629/2822-1551-988/904-823 again second gears in bold .
the TF can do amazing things, if you let it.

But
There is no argument in wanting a manual trans, just for the experience. And in the case of the AX-15, the ratios are pretty good.
You just gotta hope it doesn't blow up.