I ran that box for three or more years behind my 367, and with three different cams, trying to like it. After breaking the third one, I got me a regular Commando and a GVod; problem solved. My complaint was that the gear ratios were just too far apart.
The thing is that the Convertor of any automatic transmission, is a Two-speed device, with an infinitely variable ratio between the two gears, and it's all automatic.
At zero mph, and at WOT, the TC will start in it's lowest ratio which is often at about 1.8
At top speed, still at WOT, the ratio may be down to 8% slip.
At cruising , the slip might be 3 or 4%
That makes your 3dpeed LU trans, act like a 4.5 speed.
Lets look at what I call road gears, which incorporates the rear gear and TC slippage.
Lets use the A999 and 2.94s
the trans ratios are; 2.74-1.54-1.00
Incorporating the 2.94s you get; 8.06-4.53-2.94
Adding the TC to first gear at 1.8@zero mph, you get; 14.51/8.06-4.53-2.94
Adding slip in each gear, say 15% at the top of first, 12% at the top of Second, 9% at the top of Third I get; 14.51/9.27-5.10-3.21 and 2.94 LU. I call LU a half gear; So this totals 4.5 ratios with the lowest automatically shifting. Lets stack that up with a TKO
The TKO is 2.87-1.89-1.28-1.00 and your choice of overdrives is .68/.72/.81
You need a starter gear of About 10/1 and a Final Drive of say 2.76. But the most important gear for a streeter is Second. So lets set the TKO up with a 5.10 ratio in third gear, to match the A999/2.94s. So then 5.10/1.28= 3.98s rounds to 3.91s in the back. Ok here we go, the road-ratios are
11.22-7.39-5.00-3.91-2.82 (.72od) Lets put the A999/2.94s under it; V
14.51-9.27-5.10-3.21-2.94LU as you can see,
the A999/2.94 is better in the first two ratios, same in third, and similar the rest of the way. It's really hard for me to love the TKO roughly $4000 bucks worth, when the A999 is already in my stable....
BUT, there is one fly in the ointment; that 14.51 ratio, as soon as the car starts moving OR if the tires spin, immediately starts to diminish towards it's 9.27 ratio. So, if your engine cannot sustain the torque input to the TC, it will fall on it's nose and perhaps even bog. Therefore Stall selection becomes important. Not to worry tho cuz you got a LU on the other end.
The other options are, a bigger engine with inherently more low-rpm torque, or more cylinder pressure to start with.
Finally; I have run that A999/2.94 combo, except no LU. but with a 2800TC; behind a lo-compression 318, and I liked it so much, that I tried it with 2.76s which I liked well enough to try again the following winter. With 2.76s this WOT combo was,
13.61-8.70-4.76-2.99- no LU compared to the;
11.22-7.39-5.00-3.91-2.82 (.72od) the TKO
Again, the Torqueflite wins where it counts, with top of second being 67mph @4000 which is about the powerpeak of the smoggerteen.
with 2.76s, 65=about 2300@3% slip
Almost everything I talk about, I have already tried.
If it seems like a lot, it's because I am coming 69 in June and have been messing with cars since 1969; which, at over 50 years, is a really really long time, lol.
For example;
If you need a narrowed 8.75 with Moser axles, 10 or 11" brakes, and say 4.88s, and a Trac-loc or a spool, I might be able to help you with that.lol.....
