the 727 adds more durability- long life for taxi and police , trucks
and is stronger for really high hp applications
a lot of work to convert if you absolutely do not have to
but 998 999 would work fine
just add a transgo reprograming kit- not just a shift kit
and a lock up is proven on the street
998 (31RH) has 4 clutches and -narrow or wide ratios so check
999(32RH) gives you 5 clutches all were wide ratio AFIK
and a double wrap reverse band compared to 904
- 1984-1989 Chrysler M platform vehicles with AHB 318 4bbl police option (Dodge Diplomat, Plymouth Gran Fury)
- 1994-2003 Dodge Ram Van B150 with Magnum 3.9L V6 engine
- 1994-2003 Dodge Dakota with Magnum 3.9L V6 engine
To identify a lock-up, count the splines on the input shaft. Non lockup units will have27 splines while the lockups will have 26 splines.
Also, the lockup will
have a passage drilled through the center of the input shaft. If a
small wire can be inserted more than an inch into the shaft, it is a
lockup.
For the 998, on the pass side, in the back, above the pan's corner, there is a round shape in the casting which is the servo bore,
and the 998 has 2 "gusset ribs" above this "servo cylinder" visible on the outside of the case.
TF-998/9 can be identified from the TF-904 by the two external ribs on the case above the rear servo.
The 904's lack these "gusset ribs".
Understanding is the 998's have a 4 gear planetary, where the 904's only have a 3 gear, and the 999's I believe have a 5 gear planetary.
TF-904 has 3 pinion planetaries and a single wrap rear band.
TF-998 has a larger front servo than 904 , 4 pinion planetaries, and a double wrap rear band.
TF-999 is same as TF-998 except for 5 plate front clutch, and a wider front band.
A-904 transmissions from their inception until 1967 have 18 splines on the input shaft.
A-904 Non-lockup transmissions from 1968 onward have 27 splines.
A-904 Lockup transmissions appeared in 1978, and have 26 splines.
360- Magnum converter/ flexplate weights are different than LA
IMHO it is best to use the weight on the flexplate or B&M so you have more converter choices
quote from 401AMC Pacer (I also own a pacer with a 999)
"Several reasons I'm stuck on a 998 (or 999) is because it's a direct bolt in replacement for a 904 and offers nearly the same strength as a 727 but doesn't weigh anywhere near as much and has less internal power loss."
although the904-99 and 727 have different lengths,
the distance between the front of the bellhousing and the centerline of the transmission mount is the same 22.66" for both transmissions.
