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904 race trans wish list

Posted By: dc426

904 race trans wish list - 07/22/09 04:23 PM

If you were to go from a 727 to a 904 in your low 10 second A body. What would you be looking for in a list of parts to build a race 904 transmission and a converter recommendation for same? I'm looking for a parts list that will withstand a 3200 pound A body on a trans brake running Cal Tracs. this is not an "open check book" situation, so please be budget minded.
Thanks,
DC
Posted By: S/ST 3040

Re: 904 race trans wish list - 07/22/09 04:33 PM

A multi-spring retainer for high gear drum and swap in your existing
valve body. (about the only interchangable component)

Converters are obviously different and aftermarket units fit 68-up.
If your current converter is working to your satisfaction, have
the manufacturer duplicate it on a 904 core.
Posted By: scottb

Re: 904 race trans wish list - 07/22/09 05:05 PM

Harden input shaft
Posted By: 70AARcuda

Re: 904 race trans wish list - 07/22/09 05:13 PM

5 clutches in the front clutch pac
Posted By: DavidDean

Re: 904 race trans wish list - 07/22/09 06:52 PM

Rollerized output shaft support

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Posted By: dc426

Re: 904 race trans wish list - 07/22/09 11:20 PM

anyone else wanna add anything?
Posted By: turbocolt2.4L

Re: 904 race trans wish list - 07/22/09 11:56 PM

rollerized gov support a must ,wide pump gears if you machine little off top end plate you can fit 5 frictions in forward too and all the above.I dont think you need harded input shaft i have a stocker in mine over 500 hp to wheels 2500 lbs car leave 6000rpm on brake 27 psi of boost.mid 9's.

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Posted By: Quicktree

Re: 904 race trans wish list - 07/23/09 12:13 AM

I wouldn't swap
Posted By: dartman366

Re: 904 race trans wish list - 07/23/09 12:15 AM

Quote:

anyone else wanna add anything?

same oiling mod's and build procedure's as a 727, high quality clutch's, band's, bushing's and thrust bearing's, and keep clearance's tight.
Posted By: LA360

Re: 904 race trans wish list - 07/23/09 12:53 AM

Try and find a core with steel planetries if you can.
Sell your 727 and convertor to pay for the parts of your 904.
Parts I'd buy-
Roller rear support.

re-use your brake or pick up a Griner or similar.

Quality rebuild kit including new bushes and thrusts etc.

If your budget allows an aluminium drum and a hardened Input shaft would be nice.

We usually run a bIgger neck (BW35) as well.
AL.....
Posted By: dc426

Re: 904 race trans wish list - 07/23/09 12:59 AM

Quote:


We usually run a bIgger neck



not sure what your talking about here?
Posted By: dartman366

Re: 904 race trans wish list - 07/23/09 01:18 AM

Quote:

Quote:


We usually run a bIgger neck



not sure what your talking about here?

I think he may be talking about a thicker wall pump drive hub.
Posted By: Chris2581

Re: 904 race trans wish list - 07/23/09 02:19 AM

Quote:

I wouldn't swap




I wouldn't either.That 727 is going to last a lot longer than the 904 will,even if the 904 is race prepped with all the goodies.
Posted By: topfueldart

Re: 904 race trans wish list - 07/23/09 02:57 AM

Quote:

Quote:

I wouldn't swap




I wouldn't either.That 727 is going to last a lot longer than the 904 will,even if the 904 is race prepped with all the goodies.



It all depends on what its going behind, your intended use, and how well the trans is built... SS/AH Hemi Cars wouldnt run 904 internals if it werent worth it.
Posted By: LA360

Re: 904 race trans wish list - 07/23/09 03:00 AM

Quote:

Quote:


We usually run a bIgger neck



not sure what your talking about here?



larger diameter neck on convertor

you will gain ET with the 904, but it will come at a cost
Posted By: S/ST 3040

Re: 904 race trans wish list - 07/23/09 03:10 AM

Quote:

SS/AH Hemi Cars wouldnt run 904 internals if it werent worth it.



Oh, it's worth it.......but, they don't use that lightweight stuff because it strong
and I doubt there is one thing in them that originally came in a 904.
Posted By: topfueldart

Re: 904 race trans wish list - 07/23/09 05:19 AM

Quote:

Quote:

SS/AH Hemi Cars wouldnt run 904 internals if it werent worth it.



Oh, it's worth it.......but, they don't use that lightweight stuff because it strong
and I doubt there is one thing in them that originally came in a 904.



I understand your point. I just dont agree with the viewpoints of many Mopurists that its 727 or nothing. 904's have their worth as well. I already have a good number of performance 904 parts, so for me, I'll stick with the 904 until im proven its not worth it anymore. Which will be much farther than most would ever dare.
Posted By: 70blackfish

Re: 904 race trans wish list - 07/23/09 05:40 AM

ask Dave at pro trans, I dont think he will sell you something you dont need....
Posted By: Mcode69

Re: 904 race trans wish list - 07/23/09 06:19 AM

Quote:

Try and find a core with steel planetries if you can.
Sell your 727 and convertor to pay for the parts of your 904.
Parts I'd buy-
Roller rear support.

re-use your brake or pick up a Griner or similar.

Quality rebuild kit including new bushes and



thrusts etc.

If your budget allows an aluminium drum and a hardened Input shaft would be nice.

We usually run a bIgger neck (BW35) as well.
AL.....




Find a '76 or later 904 for a core, they come with the steel planetaries. The pre '76 ones have aluminium planetaries and are a weak link.
Posted By: dc426

Re: 904 race trans wish list - 07/23/09 01:24 PM

Quote:

larger diameter neck on convertor



how is this accomplished? what about the pump, what do you do there?
DC
Posted By: LA360

Re: 904 race trans wish list - 07/24/09 12:53 AM

The diameter of the Borg Warner 35 convertor neck is around 3/16"ish bigger than the 904. Basic the company making the convertor machines up a stepped neck, the diameter that drives the pump is the standard size, the diamter that runs on the pump bush is the larger size. Most importantly, this adds thickness to the bottom of the drive slot where 904 necks are prone to cracking.
Basically every reputable convertor shop in Australia has this as an option (Big Neck). Autoflite Engineering (Dominator Convertors) were the first to do this many years ago. I have a pic somewhere, but I would have to dig it up.

AL....
Posted By: dc426

Re: 904 race trans wish list - 07/24/09 01:28 AM

hmm, interesting. I haven't heard of this in the states....anyone?
DC
Posted By: LA360

Re: 904 race trans wish list - 07/24/09 02:44 AM

How Plentiful are Borg Warner 35 Automatic transmissions over there? They are everywhere over here.
AL.....
Posted By: dusturbd340W5

Re: 904 race trans wish list - 07/24/09 03:19 AM

Quote:

hmm, interesting. I haven't heard of this in the states....anyone?
DC



Chris many shops here in the states offer this on 904 converters.
Posted By: MoparJoe

Re: 904 race trans wish list - 07/24/09 03:50 AM

Quote:

Quote:

Quote:

SS/AH Hemi Cars wouldnt run 904 internals if it werent worth it.



Oh, it's worth it.......but, they don't use that lightweight stuff because it strong
and I doubt there is one thing in them that originally came in a 904.



I understand your point. I just dont agree with the viewpoints of many Mopurists that its 727 or nothing. 904's have their worth as well. I already have a good number of performance 904 parts, so for me, I'll stick with the 904 until im proven its not worth it anymore. Which will be much farther than most would ever dare.



You have about another .75 sec before you start mowing thru anything stock in a 904. One of my friends went thru this with his, on a 11.2 car the stock 904 would go for 2 years with just the standard performance rebuild, manual VB and small snout converter.

When he swapped to a better motor that runs 10.5's it started getting 3-4 runs before the clutches were gone, when the clutch issue was fixed it started breaking cases and input shafts every few passes. He has a built 904 in it now but the price is almost the same as an entry level lenco.
Posted By: 70AARcuda

Re: 904 race trans wish list - 07/24/09 04:30 AM

Quote:

hmm, interesting. I haven't heard of this in the states....anyone?
DC



go to turboaction.com

click on instruction on left side of page...

then click on tech tip #6...,,,and it reads,,,and it has pictures...

It is not unusual for a Torqueflite 904 converter to crack the pump drive neck as shown above. Turbo Action to help stop this problem, was the first company to use chrome moly pump necks. This helped, but you can help this problem even more with our help. Machine the ring on your reaction shaft off and then request to make your converter pump neck solid on the inside (N0 Step). If you machine this ring off and you do not make pump neck thicker, you will not hurt your transmission or converter. If you install a solid neck converter on a stock transmission, you will have problems.
Posted By: LA360

Re: 904 race trans wish list - 07/24/09 08:04 AM

The ones we use are a little different, see below



AL....
Posted By: S/ST 3040

Re: 904 race trans wish list - 07/24/09 12:37 PM

What really would be neat would be, to modify the 904
to accept the 727 converters.

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