904 vs 727 torque flight?

[Harper]

what are the differences (in how much power they can handle) 904 vs 727 does anyone have pictures of each?

who builds a good roller 727?

does John Kunkel  build 727's?

is it best to buy a new valve body or rebuild an original? for performance and street use?

when using a stall convertor for street and track use, what is the ultimate goal (to be able to launch without blowing off the tires correct? Since these 440's have a ton of torque would it be safe to say that a 2500 to 3000 stall would be plenty of launch for a street car? or would you aim higher? my goal is a street car that would be also decent at an occasional drag strip outing.

sorry for all the questions but i am trying to build my knowledge base here....and i know there is a lot of good info on this board.

[c00nhunterjoe]

A 904 behind a big block is not something for street use. Thats a drag race only setup. But to answer the question, in the drag race scenee, the modified 727/904 guts are well over 800hp on stock cases. But again, race only.

Your other questions are too vague. It depends on what you have built as far as power output, rear gear, and tires.... some guys prefer the stock stall, others want more, and the combo plays a major role there as well. But, the general average consesnus is for mainly street use, a flash speed of 3k is about the max for a happy medium. Some like more, others less. Some motors need more, others dont need it. It all depends.
   By roller 727, are you talking about converting the brass bushings to roller bearings? Or roller as in complete bolt in ready? For a mostly street car on street tires, a basic hp 727 overhauled is more then enough. A reprogram kit should do the trick on a good core valve body.You dont need to go crazy unless you start putting sticky tires and alot of torque through them.

[Harper]

when i say "roller" when talking about the transmission i am referring to Roller planetary's,  roller thrust washers etc. otherwise eliminating unnecessary drag through out the transmission. I know i have owned a roller c4 in my ford mustangs, but it was suppose to be a "Race only" trans. I am curious if this modification would survive on the street if the cooling for the trans and convertor were sufficient?

typically a higher stall conveyor is smaller in diameter and lighter but does build more heat (at least thats what i was told)

at the time i was told to use a stack plate design external transmission cooler (especially since i had a high stall convertor). I did drive my car to the track 20 or so miles away, but with my 4:10 rear gear i only drove it once because i was scared that i could possibly overheat it and didnt want to ruin my $650 art carr convertor. I sent it (the convertor) back three different times then eventually put that same trans and convertor behind my 472 big block ford in my drag only 79 Mustang. I was able to get 30-35 passes out of the clutches before a freshen up (i never broke the trans). and eventually sold it.

i definitely do not want to be pulling my transmission out every 6 months to freshen, therefore the reason i am will to go with that ginormous 727 lol

i kinda understand that the 727 has LARGEr clutches compared to the 904 and this would probably be the best choice behind a big block mopar engine, so i will probably stick with a 727. But i do not want to buy a trans thinking its a 727 only to find out its a 904 lol

just trying to do my research.
the pictures on the transmission thread (for some reason) i can not view.

[Harper]

is this a 727 or 904?

[Bronzedodge]

From the part number it would appear to be a 727 from a 73 440.   Likely a cast crank, externally balanced motor; judging by the weights on the converter.  The visual cue is the "kickout" in the pan rail by the dipstick hole.  904's are more square.

[Harper]

Bronzedodge,
thanks
i have seen so many different styles and that one appeared to be a 904 but the seller said 727, sometimes its hard to tell the difference 

[c00nhunterjoe]

Im not following why you are leaning towards all of theses modifications for a car you are saying is not a drag car? Again, no need for all the conversions and upgrades, even on a weekend bracket warrior. 30 passes before overhaul tells me something is seriously wrong. The mopar stockers i run with go 2 years of racing before freshen ups, which is just a band replacement since its 600hp on a 904 band.  The pushbutton 727 in the 63 dodge has been together since 2009 with no freshen ups and is a 10.40 car at 126-129 mph. Also sees some street miles. Nothing crazy inside, manual valve body, bolt in sprag, steel drum, basicly just high rpm heavy duty parts. 8" converter flashes at 6k. If built right and maintained, it should last you a long time.

[c00nhunterjoe]

Pans are easy id

[Harper]

Im not following why you are leaning towards all of theses modifications for a car you are saying is not a drag car? Again, no need for all the conversions and upgrades, even on a weekend bracket warrior. 30 passes before overhaul tells me something is seriously wrong. The mopar stockers i run with go 2 years of racing before freshen ups, which is just a band replacement since its 600hp on a 904 band.  The pushbutton 727 in the 63 dodge has been together since 2009 with no freshen ups and is a 10.40 car at 126-129 mph. Also sees some street miles. Nothing crazy inside, manual valve body, bolt in sprag, steel drum, basicly just high rpm heavy duty parts. 8" converter flashes at 6k. If built right and maintained, it should last you a long time.

i tend to overthink a build when building for performance. 
Its not strictly a drag car however if i want to drag race it i want it to be capable of staying together and win, and not break down.
the 727 is heavy duty enough i should have no worries.
If i could get 3-4 years out of a rebuild i would be happy.
i have no problem with a manual valve body.actually it would be cool to have a put it in drive and go auto, and i could always manually shift it if i was feeling sporty

thanks for the gasket clarification. New to dodge automatics for sure...all info appreciated.

if ya'll think your getting a good laugh wait until i try to rebuild this thing and post help questions 

[Troy]

Without causing yourself a lot of issues... big block and small block engines have different (non compatible) bell housing mounting configurations. 904s only came behind small blocks from the factory. There were big block and small block versions of the 727: All big block automatics were 727s and only high performance small blocks (ie 340) got the 727 (until later in the 70s). So, that means small block 904s and big block 727s are fairly common and obtainable (ie cheap). In stock form, the 727 is the stronger transmission. It's also super easy to install behind a big block. It is possible to mount a fortified 904 behind a big block but it seems like an awful lot of effort and money to me.

I'll go out on a limb and say your converter choice is going to depend on your cam, tire size, and rear gear. It's all a package to make the car perform.

Troy

[Harper]

thanks Troy, anytime i can learn i am grateful, I will stick with 727.

[Harper]

ok so i purchased this trans today and brought it home.

a couple questions
what is this circled (white circle) is it a counter weight?

Is the flywheel built onto the convertor?

how many different balences were made on 440 mopar engines?
so if i use this trans and convertor it should bolt up and work and have the correct balance for the engine? any 383/440?

[Harper]

Evidently the 1967 thru 1981 440 engines are all balanced the same?

and 24 spline input shaft...

[c00nhunterjoe]

There are internal and external balanced big blocks. So 2 designs. The trans doesnt matter, the converter will be weighted depending on your crank. There is still a flexplate, but yes, the starter teeth are on the converter. Big chunk of steel is a damper.

[Harper]

There are internal and external balanced big blocks. So 2 designs. The trans doesnt matter, the converter will be weighted depending on your crank. There is still a flexplate, but yes, the starter teeth are on the converter. Big chunk of steel is a damper.

I hate it when they do internal/external balancing...it almost always seems to confuse someone and case vibration issues...Ford did that shit half year on the V6 mustang engine between 1999 and mid year 2000... big issues

[c00nhunterjoe]

Its not too bad. On the floor, its easy to tell the difference in cranks and balancers and cast vs forged. Aftermarket parts are readily labeled amd the converters will be universal with a removable weight typically.

[Nacho-RT74]

white circle is an harmonic balancer counterweight.

I'm thinking if THAT will save my harmonic vibration problems when going over 90-100 mph and increasing ?

[Nacho-RT74]

Evidently the 1967 thru 1981 440 engines are all balanced the same?

all BB forged cranks are balanced the same but 440+6 due added weight on rods, so these engines got a diff front dampener even being forged

all B blocks casted cracks is the same case but RB ( 440 ) not... they got a diff dampener.... converters are balanced the same thought between B and RB... although later years BB got a bigger one piece counterweight

[Nacho-RT74]

about 727 vs 904... I think the oil pan shape it clears enough... but if you wanna know about belhousing diff to know what block they are...

[John_Kunkel]

As I advised Harper earlier, the transmission part number is stamped on the pan rail on the drivers side, this will ID the exact application for the trans. Pics show it to be '71-later. The 12" converter is definitely external balanced, check the two weights on either side of the drain plug, appears to be for a cast crankshaft.

The damper weight on the tail was first used on the '72 Imperial and various models after that; it dampens resonant frequencies caused by the drive train configuration.

[cdr]

Evidently the 1967 thru 1981 440 engines are all balanced the same?

all BB forged cranks are balanced the same but 440+6 due added weight on rods, so these engines got a diff front dampener even being forged

all B blocks casted cracks is the same case but RB ( 440 ) not... they got a diff dampener.... converters are balanced the same thought between B and RB... although later years BB got a bigger one piece counterweight

And 1970 up HP 440 4 barrel has the heavy rods & is external balanced , 1969 440 -6 pack is internal balance