C6 trans???

Ty Peterson

New Member
Oct 2, 2012
20
0
1
I have a 1990 gt and I just blew up my t5 and was thinking about putting a c6 in it cause I'm tired of going through trannys. I know it's gonna take some hp away but it's better than spending money on new trannys everytime I get on it. I also want a auto instead of my 5 speed to so will it fit and what all needs to be done to convert? And another reason I wanna do it is because I can get one for pretty cheap. I'm also about to stroke it to a 347 so I think a c6 will hold up better than a t5 or c4
 
  • Sponsors (?)


I just contemplated the same thing. Blew up third gear in my g force t-5... Put a stocker back in. Thought about a 4r70w.. But I don't have the time for the conversion.. Only took about 4 hours to put another manual in.
 
Couple of things. The C6 -you will need to deal with several things- the lines, either get a new radiator or tap the existing one for the trans coolant lines, kickdown cable and bracket, shifter cable, trans mount, bell housing adapter, driveshaft yoke and length. torque converter to your setup, etc. Is there a reason you don't want a built AOD or even a tremec 5spd? Those seem to be much easier swaps.
 
Bellhousing adapter? No sir.
A typical SBF C6 will bolt right up to the block without any problems at all. I've got a mild 351W (same bellhousing pattern as a 302) with a C6 in my truck. Has a nice shift kit and has the diesel C6 hard parts (yes they're interchangeable) and that thing has taken miles upon miles of abuse. The only downside to the C6 is they're a pretty healthy sized transmission. They're heavy as hell and may not even fit in the transmission tunnel of a foxbody. I've always wanted to try and see if one would fit but my car was a 5 speed so I'm leaving it that way.

Also you could just mount an external cooler in front of the radiator instead of getting a new one
 
Bellhousing adapter? No sir.
A typical SBF C6 will bolt right up to the block without any problems at all. I've got a mild 351W (same bellhousing pattern as a 302) with a C6 in my truck. Has a nice shift kit and has the diesel C6 hard parts (yes they're interchangeable) and that thing has taken miles upon miles of abuse. The only downside to the C6 is they're a pretty healthy sized transmission. They're heavy as hell and may not even fit in the transmission tunnel of a foxbody. I've always wanted to try and see if one would fit but my car was a 5 speed so I'm leaving it that way.

Also you could just mount an external cooler in front of the radiator instead of getting a new one


Not arguing with you but I thought the bolt patterns are different as there are 3 different C6 bellshousing versions. Small block, big block and FE block. Which one does the OP have?

Ford C4 & AOD (5 1/8" center to center top two holes) 289, 302, 351c, 351W

Ford C6 (6" center to center top two holes) 332, 352, 360, 390, 406, 427, 428

Ford C6 (7 3/4" center to center top two holes) 429, 460, 351M, 400M

I've never put a C6 behind a small block and you have so I will defer to you. Just giving my 2 cents.
 
C6 has a non-removeable bellhousing.
They do make one for an SBF, you just have to find one.
It's not like you can grab any C6 and change the bell.

The trans mount is much further back than a C4, so you have to move the crossmember back.
The driveshaft will need to be shortened.
The driveshaft yoke is larger.

If your radiator is not for an automatic, you will need to get one that is.
They say you can just get away with an external cooler, but I wouldn't trust it.
I would do the radiator swap and an external cooler. Heat is the enemy to an auto.

Probably need a 164t flexplate balanced to your engine, which I assume is 50 oz.
 
  • Like
Reactions: 1 user
I've never put a C6 behind a small block and you have so I will defer to you.


I didn't put it in there. That's how my truck came lol. Ford offered the C6 with the same bellhousing pattern as the C4/C5 and AOD. There's plenty of trucks still rolling around today that are half tons with small blocks and C6's :shrug:

They even put it behind the straight six since they were so torquey.

http://en.wikipedia.org/wiki/Ford_C6_transmission
 
C6 has a non-removeable bellhousing.
They do make one for an SBF, you just have to find one.
It's not like you can grab any C6 and change the bell.

The trans mount is much further back than a C4, so you have to move the crossmember back.
The driveshaft will need to be shortened.
The driveshaft yoke is larger.

If your radiator is not for an automatic, you will need to get one that is.
They say you can just get away with an external cooler, but I wouldn't trust it.
I would do the radiator swap and an external cooler. Heat is the enemy to an auto.

Probably need a 164t flexplate balanced to your engine, which I assume is 50 oz.

Finding an SBF C6 is the hard part.
Also if you have a big enough external cooler, it's okay. Hayden makes a nice quality one but the cream of the crop IMHO is a factory Ford unit. On the Superduty's with the 6.0, their trans cooler is MASSIVE. About as wide as our radiators on our cars and about 9 inches tall. When we have guys come in with 7.3's for trans jobs, we mount a 6.0's external cooler and use JUST it. Been working fine for us for years.

EDIT: finding an SBF C6 that's not still going is the hard part. I've had more people coming in for rebuilds on SBF C6's than people trying to sell cores.
 
I didn't put it in there. That's how my truck came lol. Ford offered the C6 with the same bellhousing pattern as the C4/C5 and AOD. There's plenty of trucks still rolling around today that are half tons with small blocks and C6's :shrug:

They even put it behind the straight six since they were so torquey.

http://en.wikipedia.org/wiki/Ford_C6_transmission


I meant bellhousing adapter, not swap the bell housing as its non removable. Too much college football and posting. Thought you said you swapped the C6 in. Ford made 3 different bolt C6's with 3 different bolt patterns so I don't think is not simply grabbing any C6 and bolting it up. Forgot about the different tooth flexplate and no overdrive with the C6 if that matters. Like I said, never did this swap as the AOD can be built to withstand more than enough HP with a better servo, bands, valve body and the parts to swap are in practically every junkyard.

Either of you guys done this swap? Curious to see the install. Thanks
 
Will a 4r70w bolt up
Yes.. One from a v6 mustang or a5.0 explorer, or a 4.2l.. This I'd what I was going to do. But you will need to shorten driveshaft, move mount for trans. Use a secondary controller because its a computer controlled trans, or swap over to a 94-95 ecu. Like I said earlier it was a lot of stuff so I picked up a t-5 for 350$ and slapped it in..
 
Well I can't find a t5 that cheap and it'll cost 500+ to fix mine and I would really rather a auto anyways. I can get a 4r70w for about 350 so about how much more will it cost to do the swap
 
cost will depend on what you buy new or used. Does the trans come with the TQ, flexplate, dipstick etc? Most of the parts you can get from a junkyard of on the boards cheap. One thing I would not advise getting used is the TV cable if you go AOD or AODE. Buy a used one and who knows if it is stretched etc. and an improperly adjusted AOD will fry your trans in a very short time. Just bought a new one for my car at LRS for $108 bucks. Make sure you also get the brass bushing to replace the stock plastic one to connect the cable to the TB post. The plastic ones are prone to brake and you are Fuked.

Are you going to do the "J mod" or put a shift kit in the tranny?

http://www.tccoa.com/articles/tranny/transmission/index.shtml
 
Yes.. One from a v6 mustang or a5.0 explorer, or a 4.2l.. This I'd what I was going to do. But you will need to shorten driveshaft, move mount for trans. Use a secondary controller because its a computer controlled trans, or swap over to a 94-95 ecu. Like I said earlier it was a lot of stuff so I picked up a t-5 for 350$ and slapped it in..
Or go manual valve body instead of buying a controller :shrug:
 
cost will depend on what you buy new or used. Does the trans come with the TQ, flexplate, dipstick etc? Most of the parts you can get from a junkyard of on the boards cheap. One thing I would not advise getting used is the TV cable if you go AOD or AODE. Buy a used one and who knows if it is stretched etc. and an improperly adjusted AOD will fry your trans in a very short time. Just bought a new one for my car at LRS for $108 bucks. Make sure you also get the brass bushing to replace the stock plastic one to connect the cable to the TB post. The plastic ones are prone to brake and you are Fuked.

Are you going to do the "J mod" or put a shift kit in the tranny?

http://www.tccoa.com/articles/tranny/transmission/index.shtml
AODE is electronically controlled. No TV cable.
 
Well I can't find a t5 that cheap and it'll cost 500+ to fix mine and I would really rather a auto anyways. I can get a 4r70w for about 350 so about how much more will it cost to do the swap
With a decent converter I was looking at 1000+$..if you keep the stock one you can save yourself a couple hundred. You will spend almost 100$ just to fill the thing with oil.. Driveshaft needs shortened, need a shifter,shift cable,transmission lines,flex plate, modify the crossmember, trans cooler, it adds up
 
I have a c-6 reverse valve body manual shift in my 90 lx. I didnt install it was in the car when i bought it. But it fits fine and i have an aluminum radiator with an external trans cooler. I dont know how many passes were made before i got the car but i have made more than a few and its holding up great.
 
I have a c-6 reverse valve body manual shift in my 90 lx. I didnt install it was in the car when i bought it. But it fits fine and i have an aluminum radiator with an external trans cooler. I dont know how many passes were made before i got the car but i have made more than a few and its holding up great.

This is great news. If I ever decide to build a drag car, it's gonna be boosted with a C6 :D But I'm not even done with my DD yet so idk why I'm even wanting another project already.

And yeah the C6 is a tough SOB. It's just a lot of people don't like them because they're heavy and they take quite a bit of power away