If it was mine, I'ma stick-man so the NV 3500 is a no-brainer with the 3.23s. The Dakota ratios are
3.49-2.14-1.38-1.00-.73od .. with splits of
.61-.64-.72-.73 which is two wide ratios followed by two normal ratios.
With the 3.23s your roadgears would be
11.27-6.91-4.46-3.23-2.36.
11.27 is excellent for tall tires.
6.91 is an excellent Second gear
4.46 is an excellent Third for a 318.
3.23 is a nice cruiser at 55=2200, and 65= ~2600
2.36 =65@1900, and 75=2200 again excellent
For best fuel economy you will need to get a stand-alone timing computer, to be able to give the engine the ignition timing it needs at those sub 2400 rpms, which can be in the mid 50s degrees.
Obviously with a Starter of 11.27 she has plenty of First gear torque multiplication, so the engine build is almost a non issue.
Second gear, is also pretty good. a 4bbl and a free-breathing exhaust is all she needs.
Even the 4.46 Third gear is helping the stock 4bbl 318 keep pace, all the way to 90mph@5000rpm.
That 72 La 318 should still be, or might still be, a 9/1 Scr engine, which would allow a cam swap, and so would the 11.27 starter gear. The stocker IIRC was a 240/248/112, .390 lift cam. You could move up to a 252 cam without the bottom-end falling away too fast, but this is not always true with an automatic. You could go 256/260 but afterthat I would make it a solid lifter profile/ tight LSa , to help keep the cylinder pressure up. but by that time, the factory heads are getting to be a choke.
As for fuel economy the 2.36 final drive will work with anything up to about I'm guessing,
[email protected]. My guess is mid 20s mpg could be doable on the hiway from point to point, running 65=1900 with maybe 56 or more degrees of timing in a high-compression 318, and using a well-tuned spreadbore.
If your cylinder pressure falls to less than 140psi, forget high 30s
Now, if you had alloy heads and 190psi, that's a whole nuther conversation.
If you want to keep it auto, I would use the A999 gears in the A904 box with the 2800Tc.... unless the LU TC has a higher stall than 2200. the ratios are
2.74-1.54-1.00 the roadgears with the 3.23s are
8.85-4.97-3.23, mathematically but with the TC having an internal hydraulic multiplier, these numbers could be quite a bit higher; from 80% at zero mph to 10% in top gear. This custom combo has no overdrive and with the 2800TC forget fuel economy.
A better choice would be an A500 which is the same as the A999 but with an added .69od, which goes 65=1800, so economy reappears on the table..... again with sufficient ignition timing. The 2200LU TC, if she has one, may render take off slightly lazy, especially with a bigger cam. But a rear-end swap to 3.91s or even, 3.73s would cure that, and bring your cruise rpm closer to the magic 2400,for which the factory Distributor can almost reach ideal cruise timing. OOPs nope, you'll still need the timing computer.
If it was mine and I had to run an auto, on assuming a 9/1 engine, I'd go; A500/3.91s/ LU/ any stall/ Magnum heads/ a solid-lifter cam of from 212 to 218 after lashing and on a 106/108 LSa/ headers optional but not less than 340 logs, dual exhaust, and a spreadbore top-end.
With the 3.91s and 28" tires 65=2100 in LU-od; BadaBoom. If the pressure is over 150psi, then 3.73s for 65=2000, and 75=2300
If it was mine.
But if it was really mine, I'd run alloy heads and 190psi, with a stand-alone programable timing computer, and a
[email protected] after lashing, solid lifter cam, on a tight Lsa , and this requires headers for sure, and Ima installing full-length 3inchers, again. lol.
Now we're gonna lay down two long N50-15 tracks for four, five, or maybe six seconds atta crack. Oh wait those won't fit back there. Well then 275/60-15s it would have to be. lol. and five seconds for sure......
The roadgears with the A500/3.91s are;
10.71-6.02-3.91-2.70 which is killer, even with 28s.
but the hick-up is that the A500 will likely not fit in the tunnel without some metal-work. For me, that's not a deal-breaker.
Here's one more combo, which I have run, that I really liked;
A totally stock engine with nothing but a Thermoquad / headers/ an A833 Commando/ A GVod/ and 3.23s
The A833 ratios are 3.09-1.92-1.40-1.00-.78od
I like to run the GVod as a splitter which then gets me Roadgears of: 9.98-7.78-6.20-4.84, which gets me to 86mph @5000 with 88s ...... but the mainbox is still in Second gear, lol. That leaves me with
4.52-3.53-2.52 and 65=1966
Yes eight usable gears but Not one behind the other.
Second-over and Third are so close to eachother that I just pick one or the other depending on circumstance. Same with Third-over and Fourth.
My smogger-teen really liked that with the A833od and the GVod bolted on the back plus 4.30s oh yeah . The Roadgears were;
13.29-10.36-7.18-5.60-4.30-3.35-2.38, yes Seven gears with nice tight splits of
.78-.69-.78-.77-.78-.71, and 65=1860 with the 28s. I gotta tell ya, that low-compression 318 really boogied thru the gears! Total cost was under $3000C back in about 2004ish...... which bought the GVod and 4.30 gears delivered to Walhalla N.Dakota.
BTW this Barracuda with the all cast-iron 318/alloy A833 was ~ 3550 with me not in it. That's not so far from the Fury.
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