Automatic transmission

[DeCon]

I want to swap the 4 speed in my 69 charger with a 727. Do all big block B body autos fit? The reason I ask is when I first restored the car virtually every part will state all B body except charger. Chargers are a B body, but kind of all by themself.

[BleedDodge]

Yes, if it's an auto and it's a big block, it's a 727. You can get smallblock 727's, and then the 904 auto, but if you have an auto on a big block, it's a 727. A 904 has a shorter tailshaft, and you can tell a 727 from a 904 this way if they're sitting side by side on the ground or on stands or something.

I'm curious, why would you take a 4 speed and put an auto in? 4 speeds are so much fun! You can make your car dance with a 4 speed. I wouldn't have it any other way in one of these cars, that's for sure...

A B-body is a B-body. Something like a Coronet is the same frame type, just different sheetmetal.

[xs29l]

Yeah, funny, I'm switching mine to a 4-speed... I found a nice alluminum bell housing and an original Hurst shifter, they both made up my mind for me! Keep us posted

[DeCon]

I guess I should have made my question clearer. Is the cross member located in the same relationship for the mounting surface of the bell housing? I would assume the this did not stay the same over the years.
I have 2 23spline 4 gears same overall length different cross members and shifter locations?
I want to go to the auto for better more consistant launches. A 4 gear was cool when I was 17 and had a 440 with a 557/296 purple shaft 11:1 compression and mild head work. Even then the banging really breaks things, Fun yes.
As far a the "B" body your right they are primarily all the same. If you look at parts a lot of times it will state " B body except charger".
Thanks

[BleedDodge]

I believe it all bolts up, I know guys have taken automatics and put 4 speeds in their cars with almost no hassle, but you're working backwards here. I don't think you need any new parts or anything, as the automatic must have something to bolt to on the crossmember of the frame of the car it originally came out of. I'm sure it would work.

[slantsixness]

Originally Posted by DeCon

I guess I should have made my question clearer. Is the cross member located in the same relationship for the mounting surface of the bell housing? I would assume the this did not stay the same over the years.
I have 2 23spline 4 gears same overall length different cross members and shifter locations?
I want to go to the auto for better more consistant launches. A 4 gear was cool when I was 17 and had a 440 with a 557/296 purple shaft 11:1 compression and mild head work. Even then the banging really breaks things, Fun yes.
As far a the "B" body your right they are primarily all the same. If you look at parts a lot of times it will state " B body except charger".
Thanks

Your answer is:
Yes, and it did stay the same. It's the relationship between the motor mount holes on th K-frame and the transmission mount. You will need the b-body mount (not just the insert) for the 727.

I disagree that the 727, even with a reverse manual kit and "shift kit" and a "bracket racing" higher stall converter, etc. etc. will outperform your original Manual trans. But then if you want total consistency, and better reaction times, I guess it would help you.
I was always annoyed with bracket racing, because all that work you do, and then you have to hit the brakes to keep from blowing your bracket, and you can't get the car consistent in the next lower bracket. To me, it was a lot of fun, and a good bit of money sometimes, but damn that urge to blow the bracket... worse than what great reaction times improved....


Watch out for rear 1/4 panel stress cracks at the driver's door on your charger. Most B-bodies will separate around there, and an auto trans will make it worse.

Slantsixness

[BleedDodge]

Any updates yet? How is this coming along?

[slantsixness]

Yeah, what's happening with it?