I have a '66 Dart. I have yet to receive my shop manual so I have burning questions.

1). I know from someone telling me that I have a A-904 tranny, but what about rear end? what gear ratios do i have? what is my final drive? what is going on? It is a 3-speed automatic.

2). If i am able to get much more horsepower out of my slant, what kind of tranny is recommended that will bolt up to the engine, and what kind of rear end is recommended as well.?

3) is there a 4-speed floor shift tranny made that will mate up with my slant and work with my drive shaft and rear end? if so what is it?

thank you.
Caesar

If it is a stock regular performance deal then rear end ratio is most likely 2.76, maybe 2.45

For a bolt on rear end, 8 1/4" A body units are available, and are quite accomodating. 8 3/4" are also available, but a lot more rare. The 8 3/4" are cool though because you can swap the center piece and change ratios on the fly without having to rip the whole differential apart

Be aware that if you chose to swap an 8-1/4" or 8-3/4" rear for your 7-1/4" rear, you will have to have your driveshaft cut down and re-balanced (cost me about $50 when I got mine done). Otherwise, it's a bolt-in...though you'll need the u-bolts and shock plates that go with the new axle, as the axle housing tube is larger in diameter...also best to snag the e-brake cables and associated hardware and the brake flex-hose that connects the hard line on the floorpan to the T on the axle housing: you'll want this for reference even if you plan to buy a new one). If you pick your pieces right, you'll wind up with a stronger rear, larger BC / diameter wheels AND bigger rear brake drums.

Mopar offered the A-833 4-speed for the slant...here's what you need to know about that:


http://www.slantsix.org/articles/4-spee ... speed1.htm


http://www.slantsix.org/articles/clutch ... utches.htm


Stay away from the manual 3-speed column shifts: they're not a very satisfactory option.

You should consider a '74-'76 front disc brake swap as well (if you're mechanically inclined or have experienced help) so you'll be running the same bolt circle all way round. The increased stopping power is well worth the work, in my opinion.

Good luck with your swap!


---Red

Your 904 automatic ratios are 2.45, 1.45, and 1:1. This is a very good trans for Slant performance and will handle as much as you can dish out if it is built right. For serious performance you will need a high-stall torque converter. The A833 4spd is a good swap, but it can be hard to find the parts.

Lou

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Home of Slant6-powered fun machines since 1988

You could still have the ID tag on the axle. You can jack up the car, turn the rear wheel and count how many times the driveshaft turns per rotation of the wheel. The sure way is to count the teeth on the ring and pinion gears . I just changed a Dana 44 axle, it had 43 teeth on the ring and 14 on the pinion : 3.07 ratio. It's messy, but easy on the 7 1/4, that's the most precise way to know. Rotating the wheels is close enough.