Do I need more space to fit the 727?

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firefighter1

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Hi guys,

I am going from a slant six 904 to a 318 727 transmission. My cars is a '71 dodge dart swinger which originally had a slant in it. Will I have to modify the transmission tunnel to fit the 727? Also, can I use the same mounting bracket on the tail end of the 727 as I used for the 904 in order to mount it? Thanks guys!
 
The 727/318 combo will slide right in with the right motor mounts check w Schumacher's they make conversion mounts for exactly what you are wanting. Of course you'll need to upgrade your brakes, cooling, rear axle n stuff like that. You'll also need the correct exhaust manifolds for a small block in a a-body. Drivers side gets real tight. Good luck
 
Oh yeah rear trans mount goes and must go where it was. The rear tans mount point is the one constant in these things.
 
i think for your application, a smallblock 904 would be a better fit for your 318. a 904 takes less power to operate and is a touch lighter...the car, imo, will feel a little more peppier with a 318/904 verses a 318/727...
 
if you use a 727 in place of the 904 , you MUST wack 4 inches out of the drives shaft, or find one that works. you will need the 727 trans yoke. the shumacher mounts work great. your trans mount is a bolt up. i found it easier to use headers. you will need a compatable distributor for your ignition. i am running all my six suspension to this day with no problems or issues. you will want to upgrade your radiator. i got mine out of an 86 lebaron plus the shroud. i am still using my existing wiring and throttle cable .
 
mopardude318 said:
i think for your application, a smallblock 904 would be a better fit for your 318. A 904 takes less power to operate and is a touch lighter...the car, imo, will feel a little more peppier with a 318/904 verses a 318/727...
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x2
 
Thank you for all the great information guys! My car has power disc brakes, but where can i find the shumacher mounts? I will take my extra /6 drive shaft and cut it down four inches at the local driveshaft shop. I already have the yolk for the 727. since the drivetrain came all together as an original 318/727 combo out of a dodge van, i am going to keep the same setup even if its not quite as peppy(just simpler cause i know itll all bolt back together easily). I have a big block radiator and my 318/727 setup has hooker long tube headers for an A body. If they don't fit for some reason I have the small block exhaust manifolds for an Abody 318/340 engine. I have most everything except for the engine mounts. and i also don't understand what i need for my ignition system. i have an original distributor for my 318 will that work with my original slant six ignition box? if not, what do i need to change? I think i can do this swap pretty easily but i obviously dont have the experience. i appereciate all the tips and knowledge that you guys are throwing at me. After all I don't want to reinvent the wheel!
 
The 727 has a 2.45:1 first gear ratio while the 904 has a shorter 2.74:1 ratio.
I've just put a 727-based A518 OD behind a bonestock smogger 318 and the heavier/less favorable first gear(s) are a bit noticable. But you'll get used to it in a while.
 
That went straight over my head. Can you please explain to me in more simple terms and describe what your car does in the low gears when you're driving it? Thanks.

Also can someone pleas explain what distributor or what ignition box I need for this conversion? Thanks!
 
If you have the stock distributor in the 318 you don't need to change anything.


The 'longer' first gearratio in a 727-transmission gives you a slightly slower off the line acceleration, compared to a 904-transmission.
As a 727 is built stronger internally, it's rotating mass is slightly heavier aswell, robbing a bit more power from the engine.
(Originally, 727 transmission were Bigblock transmissions, which have more torque and power).

But since you're going from a /6 to a 318, you won't feel anything 'wrong' with your combo, but a smallblock-904 would be a better choice (for economy reasons).
In short, don't worry...! :)
 
firefighter1 said:
Thank you for all the great information guys! My car has power disc brakes, but where can i find the shumacher mounts? I will take my extra /6 drive shaft and cut it down four inches at the local driveshaft shop. I already have the yolk for the 727. since the drivetrain came all together as an original 318/727 combo out of a dodge van, i am going to keep the same setup even if its not quite as peppy(just simpler cause i know itll all bolt back together easily). I have a big block radiator and my 318/727 setup has hooker long tube headers for an A body. If they don't fit for some reason I have the small block exhaust manifolds for an Abody 318/340 engine. I have most everything except for the engine mounts. and i also don't understand what i need for my ignition system. i have an original distributor for my 318 will that work with my original slant six ignition box? if not, what do i need to change? I think i can do this swap pretty easily but i obviously dont have the experience. i appereciate all the tips and knowledge that you guys are throwing at me. After all I don't want to reinvent the wheel!
Click to expand...


just go shumachers website , you can find them there

you will need a car oil pan and pickup tube

if you have electronic ignition, you need a small block electronic distributor. if your car is still running points you will need to get a points SB distributor, which i have one, or you can convert it to EI. do you have an electronic igntion box now?

it is an easy swap, i did mine i about 7 hours total but i had every piece i needed. i used all my existing wiring and throttle cable. make sure you have all the kickdown and associated parts.
 
Thanks for the help. I am not to concerned about the lower horse power and torque secondary to installing a 727 vs a 904 transmission because I'm just weekend cruising the car. I think I'll just be happy having the /6 gone and small block V8. I am looking for a good 340 block to build a slightly higher performing engine in the next year.

I already have a 71 dart oil pan and pickup on the engine now. I put it on a while ago. The stock distributor for my 318 is in the engine now and from an earlier post I am told that it will work with my current setup.

Thanks everyone!
 
I think someone mentioned that I need a new drag link? Is this right? I thought that the reason I had to get a different oil pan was to clear the drag link and the k frame? If I do need a new drag link, does anyone know where I can find one?
 
firefighter1 said:
I think someone mentioned that I need a new drag link? Is this right? I thought that the reason I had to get a different oil pan was to clear the drag link and the k frame? If I do need a new drag link, does anyone know where I can find one?
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70aarcuda said:
no you do not need a new drag link...
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XS2 No you dont.
 
Your original drag link will be fine.

You also don't HAVE to change the rear end, but it may not survive if you're planning on doing burn outs or driving it hard. Plenty of Darts/Dusters etc came from the factory with a 318 and 7 1/4 rear.
 
Sweet! Thanks. That's a relief. One less part I need to worry about replacing. Haha. Shumacher mounts have been ordered. I have one last question. When I install the engine and transmission, should I have the long tube hooker headers bolted on when I lower the drivetrain into the car or should I wait until its in the car? Thanks everyone!
 
firefighter1 said:
Sweet! Thanks. That's a relief. One less part I need to worry about replacing. Haha. Shumacher mounts have been ordered. I have one last question. When I install the engine and transmission, should I have the long tube hooker headers bolted on when I lower the drivetrain into the car or should I wait until its in the car? Thanks everyone!
Click to expand...

i put mine on from underneath after the engine was in. it is easier to leave the engine attached to the hoist so you can move the engine side to side as you put the headers on the studs. but dont tighten them down until you have them both on, the engine in place and the starter is in.
 
My car made the switch from a /6 years ago. Everything fit fine, the top bolts on the 727 will be tight to reach because they are very close to the tunnel. Headers I usually wire up in place to the fenders then lower the motor in. I'm not a fan of lower the tranny with the motor. I'd rather muscle it up from below later. Now the driveshaft had to be shortened like mentioned above, but I never paid any attention if it was 4" or not. The motor mounts I used I don't remember where I got them from but their are few of choices out there. Good luck!
 
Also, make sure you have a pickle fork to seperate the tire rod ends, I am pretty sure the hookers run thru the center link.
 
you can buy a new rubber boot from summit....or you can buy a new tie rod from summit..pick which one you want to buy
 
Hmmm okay. I'm still torn between what method to use when installing the headers. I am in my garage and have a hoist I will be dropping the engine and transmission soon. Since I've never done a swap from /6 to 318 engine before, I don't know if sliding the headers up from underneath the car or loosely bolting them to the engine when lower it in is easier. Any more thoughts on this? Thanks!
 
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