904 trans beef

[cowboy4x4n]

how can i beef up a 904 trans to live behind a healthy small block.
Thanks guys

[lukedukem]

here's a good article on it if your into DIY kinda thing. if not maybe a shop can

http://www.moparmusclemagazine.com/howto/5123_904_three_speed_automatic_transmission_build/viewall.html

luke

[cowboy4x4n]

oh thanks good reading

[John_Kunkel]

That article is about a 904 build for a /6, more beef costs more money. For a healthy SB I would start with a 999 instead of a 904.

[cowboy4x4n]

What did that model come out of

[ACUDANUT]

I think he means...You need a SB 727.

[randy73]

That article is about a 904 build for a /6, more beef costs more money. For a healthy SB I would start with a 999 instead of a 904.

I had a 904 behind a 318 that was pretty potent and all I had was a HD trans kit in it and I had it for years w/no problems.

[Dino]

What's your driving style?  I say keep the 904 as is as long as it's in good shape.  I don't think you'll be able to break it.

[John_Kunkel]

The 904 is a dandy trans for performance small blocks as long as you have a decent unit to start with. Some 904's have a weak clutch count, etc. that's why starting out with a 999 gets you the best internals to begin with (and maybe a low gear set if that's desireable).

[cowboy4x4n]

mine is in good order, just plan on rebuilding a stroker 318 for alittle more.  I am not going to do a 727 if i already have a 904 that can be built to handle the power with less paracitic loss in the drivetrain.

[cowboy4x4n]

john,

I am not familiar with a 999 trans.  what year and makes did these trans come into service.  what are the benefits of that model

[Cooter]

The various Torqueflites had the same internal ratios, despite their other differences. Until 1980, they were relatively narrow. in and after 1980, a wide-ratio gearset was introduced and used in most of the 998 and 999 transmissions. This ratio was 2.54 in first, 1.54 in second, and (as with the earlier Torqueflites) 1.00 in third. This gearset, which uses a welded-steel planet cage, is noisier and less durable than the original-ratio gearset with its machined-aluminum planet cage, but the lower first and second gears helped cope with the tall rear axle ratios needed for gas mileage.

[John_Kunkel]

The 999 was introduced in '74 for use behind the 360 so it predates the low gearset which became standard in the whole 904 family in '82. The 999 has a lot of improvements over the 904 but the main performance advantage is the 5-disc front clutch and the wider kickdown band.