833 advice

[Hambony58]

Hi folks, Hambony here. Looking for advice on converting my 65 Dart 273/auto car to a 4 speed. I have a warmed up 340 and a narrowed 8 3/4 posi rear,neither installed yet. My main question is what are the challenges besides cutting driveshaft( with B833 or hemi unit) and fabricating mounts with this? I understand I will have to cut the tranny hump ( he said tranny and hump..ha ha) to accommodate the linkage.
Then taking into account this will not be a daily driver and not be a strip car- which of the 3- 1:A833 2: A833 overdrive or 3 NP833 would be preferable? The OD units would save me some gas when driving distances, so that seems ok. I am not so much of a purist that the A833 has to go in, they along with the big block and hemi trans seem more $$$.
Anyway, thanks for reading if you got this far and let me know what your opinion(s) are. Hambony.

 

[crj1968]

Well pedals and Z-Bar etc from a donor car. I converted a 68 Barrauda to an overdrive unit for a friend. Just kind of a weekend driver car. Works well for that I suppose. He likes it. the ratio gap is pretty large though so it depends on you I guess.....one moment... A-833 Transmission Gear Ratios 1st 2nd 3rd 4th
6-cyl (also 64-65 273, 74-75 318 ) 3.09 1.92 1.40 1.00
Fine-spline V8 (most pre-1971) 2.66 1.91 1.39 1.00
Coarse-spline V8 (1966-70) 2.65 1.93 1.39 1.00
Coarse-spline V8 (1971-74) 2.44 1.77 1.34 1.00
Road Race T/A; most 1971-74 fine spline 2.47 1.77 1.34 1.00
Overdrive (mid-1970s and newer) 3.09 1.67 1.00 0.7

 

[AJ/FormS]

So, if its not a DD, nor a racer, I suppose that makes it an occasional use vehicle? I have had every ratio.Wait. NP833? I havent heard that in a long while. Anyway, the tranny you will want, since you dont yet have it, is the one that best suits your combo and useage. Huh, you say?
Each of these ratios targets and fills a specific need. Things like power-band, cruising speed, noise, rear end ratios, etc, all play into the equation. When you are stuck with 4 gears, sometimes compromises have to be made.
-The O/D box has fairly wide ratios, and is best suited to low-rpm and torquey engines, or high-speed cruisers.
-The 2.47close ratio box is a great set-up for engines with narrow power-bands, or track work.
-The 3.09low/Direct box gets small engines going easier, or can help a cammy motor with cruiser gears
-The standard 2.66 box works for just about everybody else.
-Ive tried em all, and always wished for a 5 speed, for my combo.
-For a 340/stock cam, the 2.66box and 3.55s is hard to beat. The 3.09/direct will let you try 3.23s or even 2.94s.
-Or for a 340 with an upsized cam, the same 3.09box will be fun with 3.55s too, and will be alright with 3.23s.
-I did not,with my 360hp combo, enjoy the O/D box. The splits were just too much.I think it would be swell on a lower performance application; something with lots of low speed torque and a limited redline.I finally put a GearVendor unit behind it. That gave me 7 useable ratios, with excellent splits, and a Double O/D.In the end I shelved the O/D box in favor of the 3.09D box with the GV behind it.Now its a 5 speed with splitting capabilities.Very nice. If you have deep pockets the 5-speed is the way to go with the least number of compromises, and will grow with your combos. Good luck with your decision.

 

[66fs]

Driveshaft should be OK, I assume you have a slip yoke 904. Mounts are the same, just get a tunnel and center the shifter in Neutral then weld and seal it up. Use a short shaft 4 speed or OD, A or F body, to make the swap easier. Shifters are the same. Linkage is the same except for the O/D which can use a Chevy 3/4 rod, Hurst # 2132145, and the standard 3/4 O/D trans shift arm. That leaves the Bellhousing, Pedals and clutch linkage. First, get a bellhousing to match the front bearing retainer on your trans. I'd recommend going with the 10.5/10.95 130 tooth flywheel set up if you do not have anything now. Then get the clutch linkage from Passon performance or Brewers performance to finish it off. Early A bodies have their own linkage, different from 67 up A bodies, knowing that will save a lot of headaches. As for which 4 speed, I have both, I put the O/D in my 66 Formula S, and like it a lot. It will never see a drag strip, but it has never been babied either. With a 340 you should have plenty of power so think of it as a 3 speed with Overdrive.

 

[64DartGTinAZ]

Driveshaft should be OK, I assume you have a slip yoke 904.

'65 was the last year of the ball and trunnion - slip yoke started in '66