Moparchat - Home of MOPAR enthusiasts worldwide!



Go Back   Moparchat - Home of MOPAR enthusiasts worldwide! > Technical Forums > Performance Talk

Click here to search for Mopar cars and parts for sale.


Reply
 
Thread Tools Display Modes
  #1  
Old 12-29-2000, 12:29 AM
John W John W is offline
Inactive User
 
Join Date: Oct 2000
Location: Wilmington N.C. USA
Posts: 4
Question

I have a 72 Demon 340 with a 323 sure grip
(8 3/4 )and a 904 trans. The 904 needs rebuilding. Should I rebuild it or buy a rebuilt 727.(for $100) All else I would need is a torque converter.This is a driver car not a dragster. Thank's for any advice.
Reply With Quote
  #2  
Old 12-29-2000, 01:59 AM
Rex Jr Rex Jr is offline
Inactive User
 
Join Date: Dec 1999
Location: Ardmore, Alabama
Posts: 39
Cool

I would stick with the 904.The 727 is stronger but in a light car like you have a 904 will hold up fine it is also quicker than727.
Reply With Quote
  #3  
Old 12-29-2000, 08:25 AM
DartGT66 DartGT66 is offline
Inactive User
 
Join Date: Sep 1999
Location: vantaa,finland
Posts: 4,622
Post

After burning five 999's within two years behind a mild 3.23 geared 360, I would recommend the 727. After I converted, never had trans probs again.
Reply With Quote
  #4  
Old 12-29-2000, 02:55 PM
Valiant360 Valiant360 is offline
Inactive User
 
Join Date: May 2000
Location: Harper Woods, MI USA
Age: 71
Posts: 16
Post

Reality check... in all honesty here, how much faster are you really going to go, with a 904 vs. a 727 ? In the racing venue, if your looking for the last few tenths, then ok... but on a street car, or even a 11-12 second bracket car, I think the trade off in reliability vs. performance, is moot point.
I know I'll get a million arguements on this, so to each their own. For every one of you, who tells how strong the 904 is, and how long it will live behind this and that, I can come up with someone that will say otherwise. For your basic
bread & butter street car, or mild bracket car, you CAN NOT beat the performance & longevity of the 727. That I think, has been long established. IMO...
Reply With Quote
  #5  
Old 12-29-2000, 03:47 PM
Dart Dart is offline
Inactive User
 
Join Date: Nov 1999
Location: Loveland, CO USA
Age: 54
Posts: 942
Post

Speaking from experience here, I agree with Valiant360. I have a 904 in my '70 Dart that only lasted about 300 miles. My combo is as follows:

MP LA360 short block (.509/.292 cam)
Holley street Dominator intake
Holley 750 Vac Sec carb
Headers/2.5" exhaust with Supertrapp mufflers

8 3/4 with 3.55 suregrip
2500 stall converter

My 904 was rebuilt with a new front pump, deep sump pan, and a new converter and it didn't last 200 miles before it started slipping. The 904 is ok for a stock or VERY mild build in my opinion. The shaved tenths for the 904 in a serious application aren't worth the headache of Removal and Re-installation unless you are a hard core racer. The money is fairly close and you will NEVER blow up a 727 that is built correctly.
Reply With Quote
  #6  
Old 12-29-2000, 04:42 PM
Comp Chassis Comp Chassis is offline
Inactive User
 
Join Date: Apr 2000
Location: Glendale, AZ
Posts: 155
Post

For longevity, I will agree with the 727 being better than the 904, but they will live in race cars. I ran a 904 in my low 11 second drag car and never had it out in 3 years of racing. You could still read Raybestos on the clutch discs when I took it out after selling the car.

I am currently rebuilding it for my next project wich should run well into the 9's. I also have several friends that run them without trouble. A lot of it depends on paying a lot of attention to little details when you are building them.

As for ET, the 904 is good for about 3 tenths over the 727.
Reply With Quote
  #7  
Old 12-30-2000, 12:19 AM
BugEyedValiant BugEyedValiant is offline
Inactive User
 
Join Date: Oct 2000
Location: Mishawaka IN 46544
Posts: 113
Post

Hey Dart. What did you use for a valve body in your 904. Ususally you only have those problems if you use a stock one and dont have your kickdown linkage adjusted right. The adjustment is VERY important in making the thing live!
Reply With Quote
  #8  
Old 12-30-2000, 09:18 AM
DartGT66 DartGT66 is offline
Inactive User
 
Join Date: Sep 1999
Location: vantaa,finland
Posts: 4,622
Post

I used stock valve bodies with shift kits, some were TCI and others MP. When the original 999 let go the third time, I invested on a brand new MP street & strip 999 to solve the problems for good. It lasted one month. I repuilt it and it lasted five months after that. So, in went the 727 that was prepped just the same way, used the same kick down linkage etc. I think the longevity would have been helped with the use of an external cooler together with the rad unit and a deep pan with more oil. I added the cooler for the 727 with the 10" 3500 stall converter, but the stock pan retained. No problems with that one.
Reply With Quote
  #9  
Old 12-31-2000, 11:37 PM
72Challenger 72Challenger is offline
Inactive User
 
Join Date: Nov 2000
Location: Mission Viejo CA USA
Posts: 2,538
Post

Yep, heat kills transmissions faster than anything else. If you were using a high stall converter without a cooler, that's why you fried them. 904's can handle up to 500HP, maybe more, when built right AND KEPT COOL.
Reply With Quote
  #10  
Old 01-01-2001, 06:17 PM
MoPaul's Avatar
MoPaul MoPaul is offline
Inactive User
 
Join Date: Nov 2000
Location: Appalachia, OH
Posts: 360
Thumbs up

Just a quick "Amen!" You can't keep the tranny fluid too cool in my opinion. Find the biggest cooler you can fit in the space alotted. I must agree with B&M on this one, there isn't a stock cooling system on any vehicle that is adequate. The cost is minimal, it just doesn't make sense to go without.
Also, if you find someone who builds "transmissions only" you may find a specialist who has come up with his/her way of avoiding rebuilds. I know of a guy who got tired of rebuilding racing trannys for the same problems consistently. He finally sat down and just stared at his tranny for HOURS. Then it hit him. He is 24-25 and builds probably the best trannys around, and certainlny so for only a few hundred dollars. Basically, ask around your area, auto parts stores and such, for anyone they might know who is such a person. They are out there.
My apologies for a lack of detail on his method, but it is the key to his livelihood and secrecy is only proper.
Reply With Quote
  #11  
Old 01-02-2001, 08:05 AM
DartGT66 DartGT66 is offline
Inactive User
 
Join Date: Sep 1999
Location: vantaa,finland
Posts: 4,622
Post

thbe thing is that I did not use a high stal converter with the 904, it was factory stock. I used the high stall with the 727 to get the performance 'back'. Anyway, it sems like an extra oil cooler and the deep pan is always a good thought in a 904.
Reply With Quote
  #12  
Old 01-02-2001, 08:07 AM
DartGT66 DartGT66 is offline
Inactive User
 
Join Date: Sep 1999
Location: vantaa,finland
Posts: 4,622
Post

thbe thing is that I did not use a high stal converter with the 904, it was factory stock. I used the high stall with the 727 to get the performance 'back'. Anyway, it sems like an extra oil cooler and the deep pan is always a good thought in a 904. I know they can handle serious horsepower and are used in many race applications, but they require maintenance. the 727 has a lot heavier duty parts and therefore is stronger & lives longer.
Reply With Quote
  #13  
Old 01-02-2001, 11:04 AM
BB 70 Challenger BB 70 Challenger is offline
Senior Member
 
Join Date: Jan 2000
Location: Vancouver, B.C.
Age: 54
Posts: 210
Unhappy

Ok. Sorry to jump on what is John W:s original question, but this dilemma is sooooo close to my friends problem. Feel free to add your thoughts:

A good friend of mine has got this ´70 Duster with
- stock 318
- 904 trans
- 8 1/4 posi with 3.23:1 gears.

He WILL order a MP 360 crate engine. But he wants the 380hp engine and just drop it in. He has got new 1 5/8 headers on the shelve. Wants to keep the stock converter and gears for cruising and making long 200mile trips and also 13sec on the 1/4mile. You know: have it all... And NO WAY is he gonna change for deep gears and high converter.

I tried to talk him around to get the MP 300hp crate engine. Like the 904 wouldn´t stand behind the 380hp, but with the 300hp engine it would last.

SO, AM I WRONG? Can the 904 live behind a MP 300hp 360cid? Cruising, trips and all?

He keeps on showing me this Hot Rod Magazine where is that small block Crate Engine comparison with that winning Duster with 380hp engine AND the 904. What should I tell him?



Reply With Quote
  #14  
Old 01-02-2001, 03:33 PM
Comp Chassis Comp Chassis is offline
Inactive User
 
Join Date: Apr 2000
Location: Glendale, AZ
Posts: 155
Post

The 904 will live. I built a 904 and 340 for a 69 Dart that ran low 12's in full street trim and the trans has been in there for 5 years with daily street driving and a 3500 converter. He put in a 380 hp crate engine which isnt near as fast as the 340 and it is still doing just fine.

That 380 engine will be a complete dog up to about 50 mph with a stock converter and rear gears. Kids on 10 speeds will outrun him for a block. I agree with you, he probably needs to stick with the 300 engine.
Reply With Quote
  #15  
Old 01-02-2001, 04:45 PM
Dart Dart is offline
Inactive User
 
Join Date: Nov 1999
Location: Loveland, CO USA
Age: 54
Posts: 942
Post

Hey BugEyeValiant,

I used a stock valve body and the kickdown was adjusted correctly. It may be a matter of who built the thing. I am a little nervous about building the 904 again, but I have a little cash invested at this point so I may have to stick with the 904. I am having a hard time just finding someone who knows what is up with building Mopar transmissions at this point. I don't mind paying the dough, but I don't want to have to rebuild the thing again.
Reply With Quote
  #16  
Old 01-02-2001, 09:20 PM
70 charger R/T's Avatar
70 charger R/T 70 charger R/T is offline
Inactive User
 
Join Date: Feb 2000
Location: mi
Posts: 145
Post

Get the 727 better safe than sorry.
nuff said...
Reply With Quote
  #17  
Old 01-04-2001, 01:21 AM
Keith W Keith W is offline
Inactive User
 
Join Date: Jan 2001
Location: East,Tn
Posts: 38
Post

I have a 1970 Dart I restored and put a built 360 in it. I am making right at 430 Hp at the rear wheels. I ran a 904 ,the Torque converter was cheaper, and have just had great luck so far. My car is a street car but once in a year I'll drag it. No roll cage, no race anything, full street car full interior, runs a 12.20 on a Dot drag special I borrowed from a Mustang buddy(bolt pattern and offset was the same). Its had a shift kit and low first gear ser, everything else is stock!!
Reply With Quote
  #18  
Old 01-04-2001, 03:47 AM
F Cicalese F Cicalese is offline
Inactive User
 
Join Date: Sep 2000
Posts: 43
Post

Hey guys, I had a 76 B200 dodge van with a 318 and 727 LOADFLITE, I rebuilt the engine at 187,000 miles and never touched the 727 except for fluid and filter changes. Never even adjusted it. Sold the van at about 260,000 miles in '86 to a guy up the street who still drives it . It now has about 335,000 miles on it. Still never had a trans problem. In contrast, My '86 B150 van with a 999 needed about $1000.00 worth of trans work at 48000 miles lucky for me it had the 5/50 warr. Again at about 180,000 trans needed to be rebuilt. It now has 301,000 miles and I'm replacing the entire drive train. This time I think I'm doing a 300 hp/360 and a 518 auto. I haven't figured out the rear yet.
Reply With Quote
  #19  
Old 01-08-2001, 08:38 PM
Rictek's Avatar
Rictek Rictek is offline
Inactive User
 
Join Date: Dec 2000
Location: Chicago, Il
Posts: 54
Post

Some of what you guys are saying makes sense but I am more confused than ever. I recently smoked a 999 behind a mild 340. I lasted about 300 miles so I figured I had the kickdown linkage adjusted wrong. I am starting over with a brand new trans and upgraded to a warm 360. What can I do to prevent this from happening again?
Reply With Quote
  #20  
Old 01-09-2001, 12:30 AM
BugEyedValiant BugEyedValiant is offline
Inactive User
 
Join Date: Oct 2000
Location: Mishawaka IN 46544
Posts: 113
Post

Call Joe Chrisman at Tranzact. He has helped me a lot. He can set you up with a valve body or a whole tranny. Hey Dart, the stock valve body does not have even close to enough line pressure to hold the clutches in a performance application. Get a shift kit at least. Again, call Joe (317)846-4933. I had a Cheeta Valve body in my car and the kickdown band only lasted 50 passes. My car only runs 10s and weighs 3400 pounds. The thing only shifted good for about 30 of the passes and then it started softening up. The bad part is that it got a fluid change and checkup after 30 passes. What a bummer. I dont like the turbo action valve bodies because of this. The damn thing should have lasted at least twice that long.
Reply With Quote
  #21  
Old 01-09-2001, 12:40 AM
BugEyedValiant BugEyedValiant is offline
Inactive User
 
Join Date: Oct 2000
Location: Mishawaka IN 46544
Posts: 113
Post

Call Joe Chrisman at Tranzact. He has helped me a lot. He can set you up with a valve body or a whole tranny. Hey Dart, the stock valve body does not have even close to enough line pressure to hold the clutches in a performance application. Get a shift kit at least. Again, call Joe (317)846-4933. I had a Cheeta Valve body in my car and the kickdown band only lasted 50 passes. My car only runs 10s and weighs 3400 pounds. The thing only shifted good for about 30 of the passes and then it started softening up. The bad part is that it got a fluid change and checkup after 30 passes. What a bummer. I dont like the turbo action valve bodies because of this. The damn thing should have lasted at least twice that long.
Reply With Quote
  #22  
Old 01-09-2001, 04:21 AM
JOHN SHERRED JOHN SHERRED is offline
Inactive User
 
Join Date: Feb 2000
Location: ABILENE TX
Posts: 77
Post

if you are burnnig or blowing up 904 or 999 trans in street driven cars you have a serious problem something is way out of wack

my buddy has over 100,000 miles on his 904 trans in his truck and he tows a racecar every week 100 or more miles each way with no problems

i have a 904 trans in my 69 dart 3125 lbs with driver just ran 6.687 @ 102.44 mph that would be a 10.50 1/4 mile pass no problems and all stock raybestos clutches

this trans had gone over 700 passes at 11.30 before it was freshend for the new engine

lets just put it this way the 727 is the strongest trans ever built for passenger cars period the 904 is dam tuff and will take the abuse of any daily driver ever built

if you can blowup a 904 in 300 miles you will blow a 727 up in maybe 310

Reply With Quote
  #23  
Old 01-09-2001, 04:53 AM
mopar B671 mopar B671 is offline
Inactive User
 
Join Date: Jan 2001
Location: Wheatridge, Co
Posts: 3
Post

lot's of opinions, but we race a 340 challenger, and a 360 dart sport, both w/ 904's, tci kits, deep pans, regular maint, tou just havr to be careful NOT to dry hop that thing, it won,t take, we have run 2 full seasons on both cars, not 1 problem, you just gotta treat it right.

------------------
My Home Page
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump




All times are GMT -4. The time now is 07:32 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
. . . . .