904 or 727

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6T9 V-100

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Last Fall I scored a '73 Dart for $100, it was beat but ran really well. Me and 2 friends stripped it and each took what we wanted from the carcass. One of my goodies was the 904 tranny, which I was thinking about openning up and seeing if it had the 5-clutch pack, lower first gear, etc. If it didn't, I have access to a couple of A-999's and can grab bits from them for my tranny. What I am building is a budget 340; with a rebuilt ThermoQuad, a 2nd hand Eddy Performer RPM, slightly worked '308' heads, the '68 manual trans cam, headers, and a 3.55 SG 8 3/4. I am not planning to beat the piss out of this combo, but I will have some fun with it. Is it a viable tranny, or should I just go hunt down a SB727? My eventual/ultimate combo will be a 451 stroker BB w/ the 5-speed conversion, this is only a temporary thing
 
Stick with the 904 the it is lighter than the 727

I am building a 340 as well and was told this by some of the guys on here

I guess the internals in the 904 are a lot lighter so you end up with more power at the wheels.....somebody will correct me if im wrong
 
6T9 V-100 said:
Last Fall I scored a '73 Dart for $100, it was beat but ran really well. Me and 2 friends stripped it and each took what we wanted from the carcass. One of my goodies was the 904 tranny, which I was thinking about openning up and seeing if it had the 5-clutch pack, lower first gear, etc. If it didn't, I have access to a couple of A-999's and can grab bits from them for my tranny. What I am building is a budget 340; with a rebuilt ThermoQuad, a 2nd hand Eddy Performer RPM, slightly worked '308' heads, the '68 manual trans cam, headers, and a 3.55 SG 8 3/4. I am not planning to beat the piss out of this combo, but I will have some fun with it. Is it a viable tranny, or should I just go hunt down a SB727? My eventual/ultimate combo will be a 451 stroker BB w/ the 5-speed conversion, this is only a temporary thing
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I would like to see photos of your 73 Dart...
 
The 904 will be fine. Just install a good Trans-go kit and go beat on it.

BTW: I highly doubt it will have the low gear set or 5 clutch front carrier. I know 727's like the back of my hand but I am not a 904/999 guru but I think only the 999 had the low gearset. Maybe somebody will correct me if I'm wrong.
 
The '73 was a parts car that ran well...my budget builder is a '69 V-100 2-dr sedan. 87K original miles, no rot, stripper, originally owned by a grandma, and bought from her 60 year old grandson for $150. Some guys around here think I am nuts for even thinking about the 904, but the lighter weight and rotating mass (not to mention the 'free' part; made money off parting the '73) make it more viable for the first build motor on the Valiant.
 
I've got a 904 in my Duster with a pretty stout 360 (420 hp and about 435 tq). The owners of my local Dodge dealership use the internals of a 904 because of weight and put into a 727 case in all of their race cars. These are '68 Barracudas with over 900hp. In my opinion 904s are very underrated!
 
twister360 said:
I've got a 904 in my Duster with a pretty stout 360 (420 hp and about 435 tq). The owners of my local Dodge dealership use the internals of a 904 because of weight and put into a 727 case in all of their race cars. These are '68 Barracudas with over 900hp. In my opinion 904s are very underrated!
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not possible, valve body yes, a few other parts yes, but shafts, drums etc are much larger for the 727, would be like putting 318 pistons in a 440... LOL too much!
 
904 VS 727
.........
.....
Uh Oh, not this debate again:-D

for what your going to do, use the 904, it will handle all a mild built small block can give
 
agree 904 is OK for low torque light weight applications!
 
djwhog said:
agree 904 is OK for low torque light weight applications!
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i wouldnt say low torque, but everything has its limits. I know a couplle duster drag cars than run around 11 second quarter mile times, (low 11s i think?) both run 904s, never given any problems. Of course they were built up. I wouldnt put a 904 behind a hemi, but for this application a 904 will be just fine
 
my stock rebuilt 904 lasted 500 miles behind my 380 horse 340. it is at the tranny shop right now being beefed up with better clutches and a shift kit.
 
I will build it abit; the Transgo kit, low gear set & 5-clutch kit from an A-999, and a bolt-in sprag. Not sure how much HP/TQ this combo will make, but I am keeping a 400/400 number in my head. I don't believe the motor will hit these numbers, but if I build the tranny for this goal I shouldn't have any durability issues. Canner78, I feel your pain and want to avoid it at the same time. I've never tried this, so who better to ask than the more experienced Mopar folks?
 
I have a stock 904 in behind my 340 it makes 350-375 hp and I run it at the strip. been about 2 years no problems yet.
 
Looking to swap in a 727 for 904 in 72 Dart. Anybody familiar with what I might encounter and what parts I should find to complete the transplant. Thank you from Hayward Ca.
 
Marv ripes of A-1 is building 904s that will handle 2000 hp. The 904 is 25 pounds lighter than the 727. I also have a Valiant with a 410 stroker that will be getting a 904 this winter. A/S Big block maxeys have been using 904 internals for years . This is a very underrated tranny that is finally getting recognition.
 
Can the 904 explode the same way as a 727 can?
 
djwhog said:
not possible, valve body yes, a few other parts yes, but shafts, drums etc are much larger for the 727, would be like putting 318 pistons in a 440... LOL too much!
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call Dave Smith at Pro Trans in Palmdale, Ca.

most of the parts are custom made..but yes...they have 904 internals in super stock hemis...
 
I just pulled my 225/904 power trans, and have really learned alot from this thread. I have a 727, but am thinking about the 904 seriously now. Will my 225 (slant six) transmission bolt to the back of a 69' casting 440?

Thanks

Pat
 
Tacfire11 said:
I just pulled my 225/904 power trans, and have really learned alot from this thread. I have a 727, but am thinking about the 904 seriously now. Will my 225 (slant six) transmission bolt to the back of a 69' casting 440?

Thanks

Pat
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No. 6 cyl. transmssions have a different bellhousing pattern. Smal blocks and big blocks are also different from each other. So if you have a 440 you will have to run a 727 cause they never made any 904's with a big block pattern.
 
TY, TY, TY, TY.....

I was thinking about trying to rebuild and reuse, but now I know to just sell her, and put the money in a good Torque converter for the 727 I have. What would you recommend for a Stall speed. I want her to be a daily, but also want to lock up and smoke the tires when the time is right. Her new power plant is a 440, .60 over, KB pistons.

Thanks.
 
Tacfire11 said:
TY, TY, TY, TY.....

I was thinking about trying to rebuild and reuse, but now I know to just sell her, and put the money in a good Torque converter for the 727 I have. What would you recommend for a Stall speed. I want her to be a daily, but also want to lock up and smoke the tires when the time is right. Her new power plant is a 440, .60 over, KB pistons.

Thanks.
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We would need a whole lot more info than that to suggest a stall speed. Need car weight with you in it. Cam used. Heads used, ported or stock. intake and carb used. Headers or not. Gear ratio used. Probably more stuff that I'm forgetting. Most companies have an online worksheet that has places to input everything about your car and than they'll recommend a stall for it. I got one from PTC and it works real good. Especially since it wasn't a high dollar converter. Cost only $275 shipped. I think they did a good job with my combo cause it's real streetable and runs like a scalded dog. You might try them at www.ptcrace.com. That would be your best bet.
 
A Body Old Fart said:
Looking to swap in a 727 for 904 in 72 Dart. Anybody familiar with what I might encounter and what parts I should find to complete the transplant. Thank you from Hayward Ca.
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Besides the 727 and whatever internals you choose, here are a few things to think about (this includes parts I would freshen up):

New driveshaft or shorten existing one/Ujoints/Yoke
Convertor
Flexplate (SFI) and Bolts (to crank & flexplate)
Tranny Lines
Linkage
Speedo Cable (?)
Inspection Shield/Bolts


Good luck with the project.
 
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