1971' F100
2wd w/ c6
9" rear end w/3.00 gears
I am building a 390 Stroker Engine. 445 CID. It will have a boatload of torque at the lower end. Probably won't get past 5k ever.

I know the 9" rear ends are very stout, but what needs to be done to the drivetrain to ensure that it can handle the 350HP/450TQ?

This truck will not be on the drag strip, it will be used a weekend cruiser that spins the tires at will.

Thanks,
Trever

 

Unless you're going to load/tow heavy or run slicks for back tires you could probably just leave it be. Doesn't sound like you're going to beat it up. Could make sure you have good U joints though.

 

When I had the C6 rebuilt in my 69 mustang, 428 CJ, the shop installed an extra set of clutch plates and a heavy duty pump.

 

Do you have a locker in the rear? If not, you're going to need one. Spinning one tire is lame, plus it'll blow the spider gears pretty quick

I had an Auburn limited-slip in my '96 t-bird with the 8.8" rear - loved that thing. Lockup at will, but could make u-turns without embarrassing noises

I also agree with Mike, that tranny might need some lovin'.

 

People have a tendency of upgrading X amount of things and stopping just short. I used to have a 57 Chevy wagon that I installed a 396 Olds punched to 406 with a slant pan hydro. Got those parts at a bargain but couldn't afford to upgrade the *** end. I could grenade the *** end at will but, what did I really accomplish?

 

You should have upgraded the ***-end

 

In truth?
You've got a pickup truck with no real weight on the rear end and street tires.
More torque is usable but try something stupid and you'll just spin a wheel.
With that said, you could most likely just leave it as is and never have an issue if driven like a daily driver.

But you asked the question, so I'll give the answer of what I did for my car prior to the stroker build.
In my case I figured the engine would be less than 550hp/550tq but I set the goal that everything should handle 700hp with slicks to be on the safe side and not hamper engine work later.

-31 spline Moser axles
-Strange N case, with pinion support
-Eaton Tru trac
-4:30 rear gears
-built my c6 as a full roller with the best of everything I could
-added a Gear vendors unit
-4inch aluminum driveshaft with 1350series u joints front and back, and forged spicer yokes

THAN
I built the 446 engine.

Overkill? perhaps
Did I build it over night? no, this was built over 4-5 years while I drove it every day I could.
The nice part for me tho, this is my 63.5 Galaxie.... she's my baby, breaking her on the track or during spirited driving would kill me. Even more so putting the car in a ditch or into a guard rail. I don't have to worry about that really.....

Next mission is caltrac bars, boxing in the leaf spring perches, and a set of drag radials.

Drew

 

You guys are awesome, I really appreciate all the real life advice!
It is currently a open carrier 9" rear end. So spinning the one tire is a very true possibility, I need to keep this in mind. But as DeepRoots said, this will truly be a daily driver / weekend cruiser.

I am thinking about going from 3.00 to 3.50 gears. If I do that I will add a Yukon Trac-Loc or a similar limited slip differential while the new gears are being installed. This is not a penny-crunch build but I do need to keep my scope reasonable.

I do like the idea of beefing up the C6. The Truck has 217K miles and I do not believe the tranny has been opened up. Adding a fluid cooler, t-stat, mild shift kit are what I have in mind right now. Maybe a 2000ish RPM stall converter.

Please let know if you have any other ideas. Thanks again!

 

Weakest spots in the factory bits:

-axles
-pinion support
-driveshaft u-joints

Aftermarket axles, drop in are $370
aftermarket pinion support $70
driveshaft with heavier duty yokes and u-joints $400 or less

I really can't rave enough about the TruTrac as a locker. It's like an open differential until you get on the throttle.

Here are some links from my car build:
2013 Progress for my 63.5 Galaxie - Ford Muscle Forums : Ford Muscle Cars Tech Forum

Rebuilding the c6 in my Galaxie

oh and the stroker build with a link to the photobucket 100picture build :P
http://fepower.net/simplemachinesfor...pic=3868.0;all


Good luck, and rebuilding a c6 isn't hard.
Drew

 

Question for Deep Roots...Do you have a car/truck where you run a TruTrac in the snow? If so, how do you like it ? You might be the wrong person to ask since I think you live below the "snow line" so maybe you've run in the mud or wet grass?

 

Just my opinion but burning one tire is embarrassing.

 

yup, pavement only, sorry

 

Agree with 69cj....smokin'em with a peg-leg is the pooch.

@ 65Ford: Limited slip/TruTrac is the hot set up in the snow..."fun" on ice, but worth it in the snow. My next "uprade" will be doing the same for the front D60 - better than a peg leg front....I got stuck once in ice/snow, in 4 wheel, rear LS, no ballast in the bed and the grabbing front was spinning while the other tire was laughing at me.

 

Thanks to DeepRoots and Filthy Beast. I've been debating on trying a TruTrac in my 8.8 versus rebuilding the Ford Traction Lok...(for a crown vic).

For the OP, if you do decide you like spinning both tires at the same time, I think I'd try the stronger axles like DeepRoots recommended. A locking differential can pour all of your torque on one axle in the right (wrong) situations...open differentials always distribute the torque equally to both axles.