Transmission debacle

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MoparMark91

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Hey guys maybe someone could help me with a decision and possibly some insight. So i have finished my 340 to 372 stroker engine and i have 2 transmissions.

1. Unknown status 727 transission that came with a 340 block i picked up, was told it was a runner.

2 . 904- picked up unknown but was told it has been rebuilt, it was behind a 318 block i had picked up years ago


So im trying to decided on whether i rebuild one of them just so i know they are good or just run them as is? Kimd of dumb question but unsure on my next step on this. I do love 727s but just unsure
 
Hey guys maybe someone could help me with a decision and possibly some insight. So i have finished my 340 to 372 stroker engine and i have 2 transmissions.

1. Unknown status 727 transission that came with a 340 block i picked up, was told it was a runner.

2 . 904- picked up unknown but was told it has been rebuilt, it was behind a 318 block i had picked up years ago


So im trying to decided on whether i rebuild one of them just so i know they are good or just run them as is? Kimd of dumb question but unsure on my next step on this. I do love 727s but just unsure
I think most would say build the 904 as it's lighter and can hold more horsepower than the most suspect. But if you're in love with a 727 you might want to go with that because this is your hobby. I would ask why you're in love with the 727 and if it's just because of what you hear that it has bigger Parts in it?
I would rebuild either 1 it's only $120 or so for the parts. and as the person who encouraged me to do my first one said if the guy couldn't do three of those a day in his shop you wouldn't have a job very long. That put me under the mindset that it shouldn't take that long and it didn't. Not to say I did it in a few hours it took a few days for sure but that's just at home in my spare time. I was having to be careful and not get things mixed up and doing one part at a time and doing the cleaning without massive equipment...
 
Well im not super bbn in love with the 727 just i feel maybe it would serve me better but i would go with the 904 as i do also have it. Ita going in my a body 71 dart and im going to be pushing probably about 450ish hp i think?
 
Do you have a decent converter for either one? How about driveshaft?
So as for driveshaft all i have is my slant 6 driveshaft to a 904.
As for converter the 727 has ita stock 340 converter in it and the 904 has no converter at all other than i have a stock small stall one which from what i heard isnt a good idea with my engine
 
What are your intentions with the car? Drag racing? Going to car shows? When people start building horsepower they want to do something with it. Will you be running drag radials?
 
What are your intentions with the car? Drag racing? Going to car shows? When people start building horsepower they want to do something with it. Will you be running drag radials?
Taken to drag strip maybe once in awhile but more for a weekend warrior cruises and possible want to go to tracks but we will see but just mainly so hard driving and weekend fun.
 
if you plan on long smokey burn outs and just gotta have the 727, rebuild it and buy a good sprag so it wont explode! id use the 904 my self...
 
Ive always wanted to do like autocross tracks and hard road drives, thats why im beefing up my suspension alot
 
Do you have a factory floor shift? If so do both transmissions have the provisions (lugs) for the floor shift linkage?
Not sure id have to look but would u happen to know what the look difference is between floor and column. I do want to convert to some sort of floor shift in future
 
if you plan on long smokey burn outs and just gotta have the 727, rebuild it and buy a good sprag so it wont explode! id use the 904 my self...
Can i ask why? Just curious as ive heard many different aspects
 
If I was building a truck I would want to 727, if I was building a car I would want a 904... They're both pretty close to the same internally and both share the same valve body. 727 has bigger parts but generally a 904 can be upgraded pretty easily..
I'm in my mid-50s and still feel far too young to have to rely on an automatic, but when the time comes it will be at 904...
 
If I was building a truck I would want to 727, if I was building a car I would want a 904... They're both pretty close to the same internally and both share the same valve body. 727 has bigger parts but generally a 904 can be upgraded pretty easily..
I'm in my mid-50s and still feel far too young to have to rely on an automatic, but when the time comes it will be at 904...
Good to know and i lile your input, i would go woth a 4 speed but feel lile the cost and amount of work would be a lot. I would have to have a 4 speed but money getting tight as most was dumped into engine amd and suspension upgrades
 
Again sorry if i sound dumb transmissions are my weak point lol
 
Good to know and i lile your input, i would go woth a 4 speed but feel lile the cost and amount of work would be a lot. I would have to have a 4 speed but money getting tight as most was dumped into engine amd and suspension upgrades
So the sprag is a one-way device in the transmission. It gets tremendous pressure put on it when you let off the gas while it's still in first gear.. the found this to be the problem with 727's.. the cure for this is to not let off while in first gear but to shift into second before letting off the gas especially when doing like a burn off or in a wet box at the drag strip..
I actually found a great deal on my transmission years ago and had to piece a few things together.. learn a few things and curse of few words LOL..
the thing is with anything you do on this car even the money put into the motor once it's done and you're enjoying it you forget all about the expense.. and I'm not saying that we have endless budgets to do anything we want but when we set our minds to it and get it done and go through the Pains of paying for some stuff it becomes very much worth what you want.. that's why I started with if you're in love with a 727 then make it happen you'll never regret it, but if what you really want is a 4-speed don't compromise sell both of those automatics and get started doing what you want to do... I did. my car came with a 727 and I never even found out if it worked or not....
 
If I really wanted a 727 transmission I would build one and respect its limitations or it's shortcomings.. and if I was real paranoid I'd buy some kind of high end removable rear sprag and they do make them..
 
I took the granny 4-speed out of my sons Power Wagon and put a 727 in it and love it.. obviously or not doing burn offs in the four wheel drive truck LOL..
 
Both can be built to handle a lot of horsepower. Both are used for bracket racers and hold up well. 904 has a smaller case giving you more room
 
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