A998 Trans in '66 Dart

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From what I can see it's basically an A904 so yes, it will fit.
 
I'm sure one of the "know it alls" will chime in. I believe the overdrive unit is in the tail housing at the rear of the transmission and is larger in that area. So ,from what I understand,the tunnel would have to be modded. . . . correction, I believe the 518 is the overdrive trans and the 998 and 999 are just 904's that could have a lockup converter. this is JMO
 
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If I am wrong, I hope someone will correct me here but by memory A998 is a HD 904 with lower 1&2 ratios and an extra clutch disc in the forward direct drum, an a999 is the lock up version, and the a500 is the lockup o.d. version. All very good transmissions, though.
 
I had a 998 in my 66 Barracuda. It’s just a heavy duty version of your original 904. You’ll have to use the converter that comes with the 998 or one that’s 1968 and newer for a 904. 998 is non-lockup.
 
If you can afford it, a custom converter with a 998 is as good as it gets in a strong street car.
 
I wouldn't do it. The 999 has a low first gear and is totally unnecessary in a really light car like the A body. The 999 is a lockup style 904 3 speed transmission. It is not an overdrive. If your intention is to not use the lockup feature, there's zero reason to use the transmission.
 
RustyRatRod said:
I wouldn't do it. The 999 has a low first gear and is totally unnecessary in a really light car like the A body. The 999 is a lockup style 904 3 speed transmission. It is not an overdrive. If your intention is to not use the lockup feature, there's zero reason to use the transmission.
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Have you noticed a lot of the no prep guys are switching to lockup convertors now?
 
roccodart440 said:
Have you noticed a lot of the no prep guys are switching to lockup convertors now?
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No I have not. I've been out of it so long now I wouldn't know where to start anyway. Is there a certain advantage they've found?
 
RustyRatRod said:
No I have not. I've been out of it so long now I wouldn't know where to start anyway. Is there a certain advantage they've found?
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FRom what I've seen they pull harder in the 2nd 660ft and trap faster.

I've also seen them shake the tires hard at higher speeds.
 
I have a built 998 in a 66, fits the same as a 904. Low first gear, has hydraulic lockup
circuit ( no electronic controls) I had the converter rebuilt for HD service. It lowers
the RPM's 200-300 after it locks up and has a direct coupling feel like a 4 speed. I
have had loads of 904 transmissions and the 998 is better.
 
so, I am running a very mild build 318, and am simply looking for something with an overdrive that would be reliable and i don't have to chop the car u. if the tail shaft is longer cutting the drive shaft is not an issue. with that information, does anyone want to provide their ideas. i have read all of these, the majority of my driving would be mostly around town, but would like to be able to keep up with traffic on the Xway. This has a peanut rear end in it. Not a go fast, just a cruiser. Thanks all.
 
Barry Ankney said:
so, I am running a very mild build 318, and am simply looking for something with an overdrive that would be reliable and i don't have to chop the car u. if the tail shaft is longer cutting the drive shaft is not an issue. with that information, does anyone want to provide their ideas. i have read all of these, the majority of my driving would be mostly around town, but would like to be able to keep up with traffic on the Xway. This has a peanut rear end in it. Not a go fast, just a cruiser. Thanks all.
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Don't quote me but I believe you will need to modify the tunnel and the crossmember/mount for a o/d as well as shorten the driveshaft. Use the search function for A500 transmissions. There are many threads about the subject.
 
I've read TH-200r4 kits are popular for a bodies because less metal has to cut or modified to fit the transmission in.
 
roccodart440 said:
FRom what I've seen they pull harder in the 2nd 660ft and trap faster.

I've also seen them shake the tires hard at higher speeds.
Click to expand...

Now, I would assume then that this is with the converter locked up?
 
When I was messing with automatics for drag racing back in the 80's and 90's this is how it was explained to me by the guy who was building the transmissions. The 904 were original build for the slant 6, when the 273 V8 came out in 64 they made a new case for the 904 to fit the V8. Then in 67 or 68 with the new LA 318 they made a heavier duty trans and call it the 998( all 318 from then on came with 998). In 74 the 999 came out as an even heavier duty trans for the 360. 904 had 3 clutch plates, 3 clutch discs in front drum and 2 plates, 3 discs in rear drum, 998 had 4 and 4 in front, 3 and 4 in rear, 999 had 5 and 5 in front, 3 and 4 in rear. The lower gear sets and lockup converters came along at the end of the 70's early 80's for fuel mileage and the low gear set was there to get the cars moving with the 2.45 rear end gears they were putting in the cars. The 998 and 999 trans were made in non lockup and lockup.
 
@Barry Ankney the correct answers are up at the top of the thread. I and a couple others have actually used an A998. It is NOT a lock up converter trans. All have an extra clutch pack. Some have low gears, mine did not. Pat Blais (Torqueflite Patty) built mine. Another bonus of the later trans is part throttle kick down.
 
The 998 and 999 did not come until later. The late 70s or early 80s. They came about to haul the dismally heavy cars like the Fifth Avenue. This is why they were given the extra low 1st gear. To give the cars a kind of "head start" of you will from a stop.
 
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