I'm not getting much info out of the drivetrain forum, so I figured I'd ask you guys.
Ivan, I know you have a c6 in your truck, and I saw how much hp it's putting out, but what about torque? And how is the tranny holding up? I'd assume the weakest point would be the output shaft, and since you spun 44's down the road, it seemed to handle it.
Seth, Do you know anybody running 600+ on the torque side through a c6, and what kind of durability they get out of it?

 

Jared, I'll tell you who would be best to contact about this is monsterbaby. If I see him online later I'll link him this thread since he knows those trannys inside and out. My engine is about 550 horse and 525ft/lbs of torque. I was told by a couple people who knew their stuff that the stock C6 would have been right at its limits there. I'm putting on nitrous and didn't want to chance anything happening so I bought a built C6 that can handle 900hp. However, the modifications that are done to the C6 to make it capable of handling big power are not to the shafts, they're to the clutches and all that mess. Monsterbaby is running over 800hp and I believe close to 800ft/lbs through his C6 and it holds up just fine. One of the monster truck forums I browse from time to time mentioned that BigFoot trucks have gone to billet output shafts but they're also running 1500+hp. If you browse the Network 54 forum on 460's or the tranny forum you'll find there are a lot of racers in the 1000hp range that are running C6's with no problems. I think that tranny is about as tough as they come and I think it would do just fine in the turbo-diesel project. We'll see what Rob has to say when he sees this as he builds them for high power apps.

 

WOW 550 horses and 525 ft/lb is pretty nice!!

 

All I did was change heads and pop in a cam. It's no Mustange GT or anything but it'll roast those 44's like there's no tomorrow. I've got a 2500rpm stall that I had built for the truck so it "slips" a fair amount at low rpm's but once that sucker grabs look out!

 

Depending on how the finances for this project go, I may just have him build the tranny, then. I'll still have to figure out how to mount the tranny to the engine, unless the 6.9/7.3 used an SAE bell. Otherwise, it's custom adaptor time.

 

One of these days I will have the money to make my tired 400 a real screamer. Untill then I think I will re-build it w/flat tops and keep the stock heads for now till I can afford better ones and go from there! A mild cam is also in mind for a build package!! 9 more days and I will be able to play with the engine and truck so I am getting happy about that. Will an NP435 hold that much power?

 

That's about the strongest manual tranny out there. Pro has one in his truck with over 600 horse.

 

Sweet!!! I was thinking that, but I wanted to make sure!

 

the C-6 will bolt right up to a 6.9/7.3 if you get the diesel C-6. It was an option up until 96.

 

Nah, I'm sticking a v8 Deutz in front of it, about 12 litres, 490lbs/tq in it's stock na form. Maybe a pair of turbos to bring it up in the range of 900+, if I can find a tranny that fits and doesn't weigh half a ton.

 

I wouldn't think it would be too hard to have an adapter made for that bell housing to bolt it up to whatever you wanted.

 

Jared, they can be built to handle it no problem, but I really won't blather on because Ivan already steered you Rob's (monsterbaby) direction and he knows 100x more about c-6s than I do.

Yea, the np-435s can handle it. But you'll want to drill your flywheel for the biggest clutch you can squeeze in there and get a a good one.

 

building a tranny to handle 500ft/lbs isn't a problem at all. just put good quality clutches, and sealing rings in it, and it will handle that in stock form. They really don't have a problem with the output shafts on the C6 and the stock input shaft will handle a high stall high rpm application upto about 1000hp basically the hard parts are pretty good in these things.
I would run Alto Red clutches with Kolene coated steels, change the upper preasure plate on the forward clutch to add an extra friction, and steel take out the wave plates on the low/reverse clutch, and add another friction, and steel there (you can also go with a modified drum, and add another one over that for some real holding power), if it doesn't have it upgrade the sprag to a 17 roller unit, and atleast change the #9 thrust washer to a thrust bearing (you can change all of them for less drag but hte #9 takes the brunt of the punishment)
for the intermediate band I prefer the kevlar bands but on a diesel probably not needed but atleast go with a wide band, and make sure you have ateast a D code apply lever or upgrade to a R code servo (e or F code lever without the servo would be better)
A good solid stage 2 shift kit will help it live longer too, and other than that make sure your clearences are right and your good to go.

 

Sweet, thanks for the info. I found an adaptor for an SAE#3 bell to BBF c6, so since that's what's in it anyways, I'll go that route. If the parts aren't anything hard to get, then I'll just bench it and tear into it myself. It'll be my third c6 rebuild, anyways.
BTW, I've copied and pasted that post into my info folder for the project.

 

the rebuild kits with the good clutches and steels aren't hard to get. one place is oregon performance transmission, and the other is in CA both have rebuild kits on evilbay all the time for around $170 for the good one. the place in CA will also include all of the bushings for the trans, wereas oregon transmission only has the front pump bushing, and output bushing. neither of those kits contains a shift kit but both places sell them seperatly.