Need opinion 904 or 727

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txbullets

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So when I was planning my build around my stock 340 I let you guys convince me I to rebuild my 904 instead of the 727 I have to help get the extra hp out of the car. Well the build has changed as I just got a great deal on a 408 stroker so my question is do I stick with the 904 rebuild or do I move over to the 727?

727 was bought 8 years ago from from a guy who said it was rebuilt with a small stall. I have had it sitting since then. No idea if it is rebuilt or what the stall is and I don't trust people so if I go with the 727 I would probably have it looked over to make sure it is good and then since I don't know what is meant by "small" stall or if it even has a stall I would probably get a new converter

Or

904 out of my 72 dart. Get it rebuilt and buy a converter for it.

I have not bought a cam yet but probably gonna go with a mild to medium cam. Heads right now are J heads but have a feeling I might end up with edelbrock heads. Have not made that decision yet.
 
The numbers I've heard is that anything below 600hp a 904 can be built fine.

Biggest problem with the 727 is the rotating weight. If you overspeed the thing in a burnout, that is the danger
 
A 904 is easily up to your task. My 904 has a 410 Stroker with a 200 hit of NOS in front of it. So I would estimate about 725+hp is running through that trans on the Juice. It has not skipped a beat. I built it myself to the recipe you can find here by searching. Cost me about $500.00 with good parts. $ I saved I bought a converter specific for my combo from Lenny @ Ultimate $1100.00. Transbrake is from tranzact of Indy, it has low band apply. $600.00 for the Valve Body.
 
For the record this is going to be primarily street with occasional strip time. Also no tubbing so 255 tires on the back.
 
67Dart273 said:
The numbers I've heard is that anything below 600hp a 904 can be built fine.

Biggest problem with the 727 is the rotating weight. If you overspeed the thing in a burnout, that is the danger
Click to expand...

I just heard anything below 725 + hp is good on a 904 . Times have changed , I exploded 3 904 transmissions back in the 70's . Hole trough the case in 2 , all were put in the garbage , cases were not usable , replaced it with 727 never had a problem .
 
A while ago I had the same exact question. The consensus was to use the A904 and beef it up.
I've never regretted sticking with the A904/A999.
 
Look at the HP Andrews racing throws at the 904 in their track car. They can be built just fine. And look Ma, no exploding drum!
 
For what you are planning, sticking with the 904 is the cheaper alternative, and it will do the job you're asking just fine. It doesn't take much to make them hold power.
 
jerry6 said:
I just heard anything below 725 + hp is good on a 904 . Times have changed , I exploded 3 904 transmissions back in the 70's . Hole trough the case in 2 , all were put in the garbage , cases were not usable , replaced it with 727 never had a problem .
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Exploded... Hole through the case on a 904 ? This is the first I have ever heard of a 904 Exploding.... and you have had 3 Explode? Hmmmm
 
Mad Dart said:
Exploded... Hole through the case on a 904 ? This is the first I have ever heard of a 904 Exploding.... and you have had 3 Explode? Hmmmm
Click to expand...

only 2 exploded , 3rd had 2 huge cracks in the case . No phones with cameras back in the day .
 
Probably the struts and related components getting pinch in the case causing holes. Doubt it was a drum that cause the broken cases. Or Exploded as in it quit working?

A hole or an explosion?

This is an explosion...

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crackedback said:
Probably the struts and related components getting pinch in the case causing holes. Doubt it was a drum that cause the broken cases. Or Exploded as in it quit working?

A hole or an explosion?

This is an explosion...

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attachment.php
Click to expand...

Damn..... Yes that would be an explosion.......... 727?? Doesn't look like a Mopar trans.
 
not that bad , but a good sized chunk of ceasing missing , and it was not working , no fluid left in it . Should have kept those casings as the shop tossed them in the garbage . No idea what went wrong all I know is I got a lawyers letter stating my warranty was no longer valid .
 
The guy that built the drivetrain in my 74 races cars. Said couldn't break the trans if I had to. Actually recommended I use the 904 over the 727.
 
No matter which you go with, you need a good shift kit or performance valve body for firmer shifts. When I got my first car, I went through 3 stock 727's in a year until I got a shift kit installed. Afterwards, I got a 727 with a reverse manual valve body....still on the street! It was cool chirping the tires just cruising around, but got to be a pain until I went race only.

A 904 will be about .15 faster in the 1/4 mile compared to a 727 - all else being equal - converter, low gear, etc. Naturally a 727 will be stronger, but more prone to drum & sprag failure. Just be careful with your burnouts and traction. Unless you are looking for every little bit of ET, stick with the 727. If doing a price comparison, don't forget to factor in the price of a driveshaft, depending on what you have now and what trans you'll use.
 
im in the process of rebuilding a blown 904 (not exploded i may add) and to be honest, for me the 904 is 'my' best option due to not loosing those few horses through rotating mass of the 727,
BUT
to build a awesome 904 costs more to get to where a 727 starts to need modifications, (does that make sense?) but the 904 will be better behind a small block in my opinion
 
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