How many a 904 of 78 can handle torque and hp?

[RAF383]

Most of the question is in the title!

Yeah, How many HP and torque a 904 transmission bolt on a 360 can handle? (it's from an 170hp 1978 cordoba)

The main idea is to bost the engine to 380/400hp

Thanks for the help!

[LEMOOREACE]

 They are bolting 904s to Gen 3 Hemi engines these days....  You can build them up to take some good HP.  There is some good stuff out there to read if Googled.

[barracuda7199]

i have run a 904 behind a pretty hot 340 drag racing for a long time before the clutches started slipping. thats with a 3500 stall and a manual valvebody.

[7071 challenger]

Most of the question is in the title!

Yeah, How many HP and torque a 904 transmission bolt on a 360 can handle? (it's from an 170hp 1978 cordoba)

The main idea is to bost the engine to 380/400hp

Thanks for the help!

A stock 904 won't take much, in my opinion, specially from a 78 Cordoba, because in those years, they were lock-up transmission, (they were built to increase gas economy). And lock-up trans don't have good shifting range. I wouldn't built a lock-up trans, and, if you are going to swap the trans, (for a non lock-up model), I would seriously consider a 727.

Robert

[blown motor]

My 74 Challenger was a 318 car with a 904. It now has a well built 340. I believe the trans is still original but I can't be certain. It is a slap stick. How do I know if it is a lock-up tranny?
It quit shifting the day I put it away last fall so I have to deal with that when I get it out in the spring. Talked to a tranny shop but the guy doesn't seem too interested in doing anything non-stock other than adding a shift kit.

[nqkjw]

A mate of mine runs a 904 behind 650hp of R3 416 stroker.
The tranny was race prepped and coped fine getting down to 10.2s in a 3500lb car.
He gave it a 150 shot of gas,got it down to 9.7s but can't keep the tranny together anymore.
The car has been sitting idle for 2yrs after a few tranny failures while he figures out what to do next.

[barracuda7199]

Look at the input shaft where the torque converter goes if the first inch or so is smooth its a lockup. I wouldn't mess with lockup

[7071 challenger]

My 74 Challenger was a 318 car with a 904. It now has a well built 340. I believe the trans is still original but I can't be certain. It is a slap stick. How do I know if it is a lock-up tranny?
It quit shifting the day I put it away last fall so I have to deal with that when I get it out in the spring. Talked to a tranny shop but the guy doesn't seem too interested in doing anything non-stock other than adding a shift kit.

Barracuda7199 is right. If the splines covers the input shaft 'till the end, you have a regular 904. If the first inch is smooth, (no splines), it's a lock-up. And, if my memory is good, nothing is compatible between the two. Also, when you have a lock-up tranny, you will feel another shift, (like a fourth gear). I don't think that was on the market by 1974, probably came around by 77 or 78.

Robert

[RAF383]

So if I get this straight...
For an 380hp+ engine that is goiing to be 99% on the street in a A-body of 2600lbs... That might do it?

[HP2]

Didn't the 998/999 derivitives show up in the late 70s? These were stout enough that they were installed in vans and trucks.

In modified form, a 904 will live quite nicely behind a stout engine. It is in stock form where it might get dicey. I'd also say is the anticipated 380-400 horse build up a paper exercise or do you have a documented dyno sheet proving the power levels. I've seen many a 400 horse build that barely, if it all,  breaks 300 at the wheels.

[7071 challenger]

So if I get this straight...
For an 380hp+ engine that is goiing to be 99% on the street in a A-body of 2600lbs... That might do it?

If your 78 tranny is a lock-up type, I don't think it will do it. And I'm 99% shure your Cordoba  transmission is a lock-up unit.

Robert

[barracuda7199]

the 999 derivative of the 904 has a lower first gear. but the weak point i would think would be the lockup in the converter itself. where is terry at when you need him? i do not believe they make a performance converter for a lockup but i could be wrong once again where is terry? i would not hesitate to put a non lockup 904 behind your engine in a light a body. are you wanting a shift kit to firm up the shifts any?