["70" Cougar]

Well guys .. i finally did it and ordered a C6 for my Cougar it should rock pretty good. But I forgot about the flywheel and drive-shaft .. my question is just that .. motor is 351 cleavland , will the flywheel and drive-shaft still fit that were used with the FMX now that i have changed to a C6 . Also i know theres lots to consider with out more info but would 2400- 2600 stall be a little high for a street and strip (mostly street) set up like mine.. 420horse, 420flbs , this C6 and a 9inch with 2.79 rear ? any and all help will be greatly appreciated as i need to tell him soon.

thanks guys
bill

[Neal_DePape]

Originally Posted by "70" Cougar

Well guys .. i finally did it and ordered a C6 for my Cougar it should rock pretty good. But I forgot about the flywheel and drive-shaft .. my question is just that .. motor is 351 cleavland , will the flywheel and drive-shaft still fit that were used with the FMX now that i have changed to a C6 . Also i know theres lots to consider with out more info but would 2400- 2600 stall be a little high for a street and strip (mostly street) set up like mine.. 420horse, 420flbs , this C6 and a 9inch with 2.79 rear ? any and all help will be greatly appreciated as i need to tell him soon.

thanks guys
bill

I believe the flywheel will work, but your driveshaft will be too long. The C6 is a little longer than the FMX IIRC. I wouldn't run anything but a stock stall convertor with a 2.79 rear. IMHO that car really needs a 3:50 rear to work well with that combo.

["70" Cougar]

Hey thanks Neal ill call the shop back and tell them to stay stock or slightly above . I appreciate the timely feedback !

bill

["70" Cougar]

well ive done some thinking onit and i could get my driveshaft cut and rebalenced or i could try and find a drive shaft that bolts in .. I have a 1970 Mercury cougar with the sbf 351 cleavland and a C6 trans and 9inch rear end.. wat cars other then mine also would use the driveshaft that i will need.. ie would it be comets or mach1's fairlane's mustangs and or others..
just thinking i could save some money and effort. Because i only get use of this shop with the lift and tools for one sat. and i would have to put the trany in and then measure for the driveshaft length and the only shop i knwo of close is closed on sat's..
thanks again
fella's

[xntrik]

A Cleveland with 2.79 gears will fall flat on its face without at least a 2600 stall. (using 25-26 inch tires) and it will still be a dog below 30 mph with those gears.

(remember stall depends on how much torque you ACTUALLY have fighting your gear ratio and weight)

You need at least 3.25 - 3.50 gears for street, and probably 3.70s or more for that strip.

been there, done that

["70" Cougar]

Thanks for the info on the stall Xntrick . I do have 2.79's in the back door ... but.... i have a set of 3.73's up my sleeve . well.... not really up my sleeve that would be pretty aukward . But i will install them when i get around to it. In your opinion would 2100 stall be passable with the 3.73 gear . Also this car is intended for mainly street use . I do want to go to the track a few times with it but it wont be a strip only car.

thanks bill

[xntrik]

Hey, I am not the all encompassing Ford Guru here, but I have messed with a few in the last 40 years.

That 70 car has to weigh 3300, plus the driver, and Clevelands are notorious for lack of low rpm torque below 2500, even with the factory 2 bbl headed engines. But they roll on well on the highway.

It sounds like your power peaks are above 3800 rpm to get those numbers, but since you have dynoed it, what are those rpm numbers? And how was it engine dynoed, with what accessories? Is that real world installed with accessories power?

I said in the previous post......(remember stall depends on how much torque you ACTUALLY have fighting your gear ratio and weight)

You might not get the stall rpm that you think, it depends on your specific engine set up.

I see that you have to make a converter decision before installing the transmission. Soooooo.... I guess I would do the 2500 stall and drive the 2.79 gears to see how far you want to go with the rear ratio.

3.25 gear with 26 in tires (235.60x15) should net you a theoretical rpm of 2550 rpm at 60 mph. (2200 with 2.79) A stall of 2500 would fall within the useable range for cruising. (It only slips to 2500 with a hard pull)

3.73 would put you up to 2900 at 60 mph.... That is something that you would have to consider in a street driver.

too bad you didn't opt for an AOD.

http://www.jawsgear.net/store/catalog/calc.php