Being fooled in 2008 with a garage/shop...we found this today !!

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ValerianMagnum

ValerianMagnum

the little car that could
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To make this short....in 2008 at 23 years old i had a 360 in my duster with a 727... it blew up at my first summer with the duster, made a deal with a garage and they tried to rebuilt it..yes tried... ** took them 6 attemps and 2 trans cases , took months to have it worked the right way , once it was fixed it ran very good for years until last summer when i offered to buy the car back, wanted to have it inspected and the new transmission place told me that the bands were shot and the kickdown system killed the trans...as i always found that it was shifting too fast or was kinda locking or hitting at a low speed : so long story short : we removed the trans today me and my friend and ....guess what ! It was a 904 lock up with a 2900 non lock up stall ? I was freakin out and even wondering how could this freakin poor little thing could last behind a 410hp / 440 torque engine( 380hp mopar crate ) i have a two 727 with a stock stall or '68 904 non lock up with a 1900/2000 stall with a rvb still dont know what to choose and modify my driveshaft if i go 727 etc , im kinda mad and frustrated because the old trans shop who did the trans is now closed and i will never know why they screwed up and never had a 727 back in it , I honestly cant believe how long a non lock up stall survived in a lock up 904 / yes it has a * 1 inch machined surface @ input shaft*.

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You didn't immediately notice the pan shape was different?

Did I read right that you didn't own the car for a while? Maybe it got swapped then.

Nice lookin' car BTW.

I also had a 73 Duster with a 360 at age 23.
 
I was undernearh the car once in a while but i never looked at the pan until yesterday when it was on the floor ! Unfortunately..the guy who had it for 6 years never did anything on the car.
 
.............On the other hand there are plenty of guys who will tell you that a 904 can be built to handle that HP with no problem, and there may be a couple other advantages over a 727. Less power loss through the trans, and no so much a problem with overspinning the big drum
 
I've actually had WAY better luck with 904's than I have with 727's.

I've lost several 727's to various issues but I've never lost a 904.

904's also don't seem to be as sensitive to that kickdown pressure issue, which can burn up a 727 2-3 shift real fast.
 
But it was never upgraged to that point..its all stock inside : beside a shift kit and a hp converter ...i just dont understand how a non lock up converter worked in a lock up trans....
 
I've also had better luck with the 904 transmissions, Currently I have one behind a 360 stroked to 416 that makes 625 at the flexplate. I run only 1/8th mile with 5.13 gears, a 29.5 x 10.5 tire, it shifts @ 6200 RPM.
 
ValerianMagnum said:
But it was never upgraged to that point..its all stock inside : beside a shift kit and a hp converter ...i just dont understand how a non lock up converter worked in a lock up trans....
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There's gotta be more too it. The spline count is different so the non lock up converter shouldn't even fit in the lock-up trans!
 
I was under the impression that non-LU converters were indeed available for use in an as built LU trans.
 
It was a fireball converter 2800/2900 rpm , as ive read on the net and in book.. a lock up trans needed a custom torque converter , ive never read that a company sold h-performance converters in the 80s or 90s ? It was a Nos unit in an old fireball box i saw it before they put it in the trans and it really flashed at 3k , i just dont understand how long it lasted...
 
You’re selling the 904 short, that’s why you can’t believe it.

While it would be better to have some of the internals upgraded beyond stock even just a basic shift kit improves the shifting enough for the stock stuff to last a lot longer. Same for the better converter.

And which shift kit is it? Makes a difference. The 904 with a few minor upgrades is more than capable of handling 410 hp, and you’ll have less power train losses than with a 727. Also depends on the use of the car, street use with street tires is totally different from drag racing with drag radials or slicks. For street use there’s no need for a 727 at all with that level of power

Plenty of guys run 904’s with a whole crap load more HP than 410.
 
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YY1 wrote: 904's also don't seem to be as sensitive to that kickdown pressure issue, which can burn up a 727 2-3 shift real fast.

YY1, do you mean if the kickdown is adjusted to shift into third way too soon? Or something else?
 
I mean that if a 727 is not adjusted "tight enough" or run without linkage installed it will burn up the 2-3 **** mechanism in very few miles.
 
72bluNblu said:
You’re selling the 904 short, that’s why you can’t believe it.

While it would be better to have some of the internals upgraded beyond stock even just a basic shift kit improves the shifting enough for the stock stuff to last a lot longer. Same for the better converter.

And which shift kit is it? Makes a difference. The 904 with a few minor upgrades is more than capable of handling 410 hp, and you’ll have less power train losses than with a 727. Also depends on the use of the car, street use with street tires is totally different from drag racing with drag radials or slicks. For street use there’s no need for a 727 at all with that level of power

Plenty of guys run 904’s with a whole crap load more HP than 410.
Click to expand...
I have No idea what kind of shift kit was installed 15 years ago but shifted very hard , fireball converter not a small unit tough... i think im gonna install a stock 727 with a stock stall to at least to finish the season , all my other trannys are 904s too ( 3x l-up ans 1x non l-up , the actual trans that we removed was full of metal particles and it was more than shot...so i dont think we can reuse any of it unfortunately.
 
My understanding is a 904 has a lower first gear and will launch better than a 727 equipped car?
 
RON REAGLE said:
My understanding is a 904 has a lower first gear and will launch better than a 727 equipped car?
Click to expand...

727 and 904 have the same gear ratios (2.45 low) up to late '70's or early '80's. then the 904 was available with a 2.74 low gear. That's also around the time when they started using lock-up converters. The lower first gear tends to help acceleration in lower HP/torque and heavier vehicles. There is a way to tell if the internal parts are 2.45 or 2.74, but I'm not familiar with the details.

Chrysler tested the 727 vs 904 in the '70's and found that, with all other specs being equal - i.e.: car weight, engine, converter, etc., the 904 was faster by about .15 in the 1/4 mile because of the lighter internal parts and less friction.
 
Demonic said:
So, whose kit do you like/prefer and why?
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Honestly I prefer a manual transmission, automatics are not my style.

My point was just that even “just a shift kit” can make a difference in the life of the transmission and how it shifts. When I had the 904 done for my Dart (number matching GT) I had a stage 2 transgo kit installed in it. Firmer shifts than the stage 1 but not a manual valve body like the stage 3.
 
I really think it was a A999....and it will explain why it lasted so long , the car was a rocket in 1st and 2nd and fell on its face in 3rd or on the street..think the lock up thing was the reason we always tought that i was the kickdown adjustement. ** i just dont know were the shop got the 2800-2900 lock up converter
 
'cause- who would want a true 1:1 drive gear?

...instead of spinning the converter faster and some of that power not getting to the wheels.
 
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