C-6 swap questions

[brewchief]

I'm planning a C-6/205 swap in place of my currant np435/dana20 and have a few questions, yes I did try to search but terms like C-6 end up with no results since they are two short or something.

Block plate? same for C-6 as C-4 or is it different? If different is it the same as any other trans?

Long or short adapter? I have both and can swap tailshaft in trans when it gets rebuilt, short looks like there will be some driveshaft interference with the oil pan on the trans, long will lose even more rear shaft length.

Body lift? I have 2" right now but wouldn't mind dropping it down to 1" if it will all fit.

I know I need a 50oz C-6 flexplate and starter, I have a crossmember that should work since it was used for this swap previously, trans cooler is handled as is shifter, what else am I missing?

I know both driveshafts will need rework, if I have to go to a high angle CV shaft in the rear it's not a big surprise.

Should be ready to pull things apart in the next couple weeks so I'm trying to get a plan going so I have most of what I need to at least mock things up.

 

[DirtDonk]

Do you already have the small pattern C6? Many were used behind the larger engines, so would not be compatible obviously. At least not without some serious adapting at the back of the engine.
But a small C6 would be out there, from a Mustang maybe with a 351W and that trans. Anything from a truck and a 351M or 400 would have the large pattern same as a 460. A trans behind a 351C might be the ticket.

If you've already got that far, I'm not sure of all the rest. There are a few members here running them though, so guessing they'll have the details if they see your question.

Good luck. It's definitely larger than a C4, but not an insurmountable problem.

Paul

 

[brewchief]

Yeah I have a small block trans, guessing it was from a 80s truck or bronco since it has the short aluminum adapter that the chain drive cases used, that has already been notched for shift rail clearance on the 205.

 

[bax]

OK, I used the long shaft because it moves the c/v joint away from the corner of the trans body/ pan. The short shaft was used with the 203. it has a reduction unit in front of it that moves the c/v joint back away from the pan. The long shaft was used with the 205. Without the reduction in front the two options put the C/v in about the same spot. The correct extension housing should be cast iron. Not aluminum. But support it and it will hold up. the aluminum one you will have to notch. The cast iron ones have the notch for the shifter. Now if you are lifting the truck at least 3 inches you can get away with using the short shaft if you get a small dia shaft made. keep in mind its the C/v joint that hits. Going full width is good too because it moves the angle out a little. I used the long shaft. I moved the rear end back one inch and eventually had to buy a hi9 to fix the drive angle. One fix screws up another. The fit is pretty good. watch the exhaust next to the servo. run your lines out of the way. You will need to make linkage, kickdown and shift. You can do it with one inch lift but you will need to relocate the emergency brake cable mount by the 205. The 205 will be right up against the underside of the body. less than a half an inch. I have had great luck with the c6 in a bronco.

 

[bax]

oh yeah you can use the c4 motor plate. Or one from an AOD

 

[brewchief]

OK, I used the long shaft because it moves the c/v joint away from the corner of the trans body/ pan. The short shaft was used with the 203. it has a reduction unit in front of it that moves the c/v joint back away from the pan. The long shaft was used with the 205. Without the reduction in front the two options put the C/v in about the same spot. The correct extension housing should be cast iron. Not aluminum. But support it and it will hold up. the aluminum one you will have to notch. The cast iron ones have the notch for the shifter. Now if you are lifting the truck at least 3 inches you can get away with using the short shaft if you get a small dia shaft made. keep in mind its the C/v joint that hits. Going full width is good too because it moves the angle out a little. I used the long shaft. I moved the rear end back one inch and eventually had to buy a hi9 to fix the drive angle. One fix screws up another. The fit is pretty good. watch the exhaust next to the servo. run your lines out of the way. You will need to make linkage, kickdown and shift. You can do it with one inch lift but you will need to relocate the emergency brake cable mount by the 205. The 205 will be right up against the underside of the body. less than a half an inch. I have had great luck with the c6 in a bronco.

Yeah i was afraid I'd have to run the longer tailhousing for front shaft clearance, mock up on the garage floor showed it would be ugly but I thought it might work with a cast pan on the trans and some grinding of the pan rail area. Hi-9 isn't in the budget right now. Rear end needs new perches to correct pinion angle so I might be able to use the version that ruffstuff sells that would move it back a couple inches.

I already have a winters shifter from when I had a C-4 so I just got the C-6 bracket kit. It will be full manual valvebody so no kickdown.

Where you able to run exhaust down each side or did both have to go to pass side to get by the case?

 

[Ourobos]

C4 came with the small 157 tooth and the big 164 tooth pattern. For the block plate and flexplate, just make sure you have the proper one for the size of your bellhousings. The AOD has ALWAYS used the 164 tooth flexplate FYI, so it wouldn't work with the smaller bell C4 or C6.

 

[bax]

you will only be able to move the rear back an inch. Any further and it will hit the gas tank when it squats. Exhaust is two into one. 2.25'' exit 3'' down the passenger side and out the corner. How much motor are you using? The c4 is easier, I had already killed / destroyed 2 AOD's before going to the c6

 

[brewchief]

Basically stock 5.0 from 92ish mustang, will see some upgrades in future.

I killed several C-4s and spent a ton of cash before going to the 435 I have now, if the only option was a C-4 I would sell the bronco and build a LS powered Jeep.

No fuel tank to hit(fuel cell in bed)but that crossmember might be an issue.

 

[Seventee]

Regular cab and crew cab pickups used the short shaft with the 205, but did not run the double cardan joint on the front.

 

[TheGanzman]

Before *I* would try to shoehorn a C6 into a Bronco, I would give this company a try:

http://www.transmissioncenter.net/c4_c6.htm#C6 Level 1

They have a great reputation for building pretty strong stuff...

 

[bax]

Regular cab and crew cab pickups used the short shaft with the 205, but did not run the double cardan joint on the front.

I have seen that before. Some of the larger trucks also used the single joint. For off road only he might be able to get away with it but it will vibrate a bunch with a lift and steep angle at any thing faster than the trail.

 

[Seventee]

I have seen that before. Some of the larger trucks also used the single joint. For off road only he might be able to get away with it but it will vibrate a bunch with a lift and steep angle at any thing faster than the trail.

Agreed, not sure if a single joint would work in an EB. The fullsize applications had the HP44 which made the driveshaft angles relatively flat to begin with, so it wasn't an issue. But that may not be the case for a LP44 in an EB. Something to consider though.

 

[brewchief]

Regular cab and crew cab pickups used the short shaft with the 205, but did not run the double cardan joint on the front.

I have thought about running no CV as it should clear but I will have to mock it up and see if the angles will work, I need output yokes for the 205 and need to see if I need a CV style or non CV for the front, rear will probably get upgraded to a 1350 so not to worried about that at this point.

Highangle driveline has a setup to run toyota joints in an early bronco with a dana 20, I might see what dia that stuff is and if he can fit it to a 205.

Before *I* would try to shoehorn a C6 into a Bronco, I would give this company a try:

http://www.transmissioncenter.net/c4_c6.htm#C6 Level 1

They have a great reputation for building pretty strong stuff...

I spent enough on C-4 stuff in the past with constant failures even when built by a very well regarded builder that I wouldn't run another C-4 even if you paid me. I would use an ultrabell and a TH400 if I couldn't make a C-6 work, I looked into it in the past and it can be done but would add a fair bit of cash over what a C-6 will cost.

 

[Justafordguy]

The C6 will hold up very well and It's not a hard swap at all.

 

[hotrod@77]

I know you all are using an automatic I have a 3 speed manual in mine and I have a 5.0 out of a 91 mustang that was a manual as well with a T5 that im getting ready to put in mine .What trans will I have to use or can I use my 3speed manual with the 91 mustang flywheel, clutch, and bellhousing?

 

[Prizefighter]

I am bringing this back since I would like to do a C6 swap also and haven't found this answer. I have a C4 now, will I need to change flywheels?

 

[bax]

NO no flywheel change.

 

[Prizefighter]

Thanks Bax! And a 1" BL will give me enough room? Don't really want to go 2".