727 or 904

727 or the 904

  • 727

    Votes: 84 35.1%

  • 904

    Votes: 128 53.6%

  • other auto

    Votes: 7 2.9%

  • switch to manual tranny

    Votes: 25 10.5%
  • Total voters
    239
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The 904 is taking some names and kickin some *** lol. Thanks everyone for the input
 
The SS/AA Hemi cars (now SS/AH) were running 727 cases with 904 internals in them built by a company called ProTrans. They were good up to 850 HP. When the SS Hemi cars started exceeding this they went back to 727 internals.

The 904 is plenty strong enough for most racing and street car activities.

The 998 was used behind the 318 (4 front clutch discs)
The 999 was used behind the 360 (5 front clutch discs)
The 904 was used behind the bent 6 (most had 3 front clutches)
 
If you want just a bolt in unit,a big/small block 727 and go for it.If you have some time and some skills,install a 518 tranny with O/D and be different and save some cash and get some gas mileage,mrmopartech
 
..I have both..the 727 seems to be king of the stip and seems to last forever..and it allows you to grow when you want w/o having to mess with the trans again..I hear it takes 5 or 10 more horse to push..with a V8..that is nada..why would you put in anything else ?? ..so 727 for me with the 2-3 shift kit..

BTW, I also have an 8 3/4 rear end even though I hear the 8 1/4 is OK..I hate doing the same job twice...


Grassy
 
904, if you're worried about strength you can just build it up a bit. i know guys that have built 904's that are 10 times stronger then a 727 and it's quicker to.
 
MANUAL! although if you have a lot of stop and go traffic then they can get a little old...
 
I like the 727. Stock it can take loads of power and built they are almost bulletproof. You have to spend quite a bit of coin to make a 904 take very much power.
 
If i were you i would just keep the 727. The cheapest tranny is the one that you already have
 
i have heard the the 727 was the best and if the draggers use it..it must be good..and it allowsx you to dringk coffee and munch a tim bit while driving..

Ian
 
I have modified my 727 with a transpack and a good superstreetfighter stall and I am really happy with the result. I am planning to use a 727 low gear set to get more power from my set up.

Don't forget that you will also have to change the driving shaft, buy another stall in addition of having the 904 rebuilt. I don't know ho much you pay in the USA, but here, it can cost around $2000 to have a strongly rebuilt 904 with a stall. An aluminium driving shaft can cost $500. Your 727 is already paid and installed...

Does these extra dollars spent for a 904 are worth the 2 thenths on the track? I'm not sure...
 
I,m installing my 408(410)with the 904,I,m having it built to handle anything HP wise.The 410 will be pushing over 500HP and if down the road I want to add some giggle juice(nitrous)I could and the tranny should handle it.New lower 1st gear,Red Racing belts,change drum,manual valve body.The 727 is a great tranny,but is getting harder to find around here.There,s still lots of 904,s kickin around which is good for parts swapping.Also there,s lots of guys racing with the lighter 904 and doing well.Anybody heard of the sprag exploding with the 727?It happens,I guess with loads of HP.My 2 cents(Canadian)which is 2 1/2 (US)LOL
 
pettybludart said:
I,m installing my 408(410)with the 904,I,m having it built to handle anything HP wise.The 410 will be pushing over 500HP and if down the road I want to add some giggle juice(nitrous)I could and the tranny should handle it.New lower 1st gear,Red Racing belts,change drum,manual valve body.The 727 is a great tranny,but is getting harder to find around here.There,s still lots of 904,s kickin around which is good for parts swapping.Also there,s lots of guys racing with the lighter 904 and doing well.Anybody heard of the sprag exploding with the 727?It happens,I guess with loads of HP.My 2 cents(Canadian)which is 2 1/2 (US)LOL
Click to expand...

Actually it doesn't take much hp to grenade a sprague although more hp can help it along. All it really takes is a drive line failure. Even 904's can explode the sprague. They are riveted in from the factory so you don't hear of as many of them exploding as 727's which are just pressed in and retained by a small set screw but 904's can do it too. For that reason the rear sprague should always be replaced with a high quality bolt in unit in either trans.
 
Thanks for the important info Fishy68,your tranny knowledge is always welcome for all to learn.:cheers:
 
Even though this thread is 11 months old, I am surprised no one has mentioned the HP difference it takes to run a 727 vs a 904. It may only be important in competition racing where you need to get all of it.
 
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