Hey anybody out there running 300 with the C6?
I will see about putting one of my F2 50 but I heard that C6 takes a lot of juice ?
Just curious no smog on mine 79 carburetor and ignition.

 

I owned a 1978 F100 with 300 six, C6 transmission and 2.70 rear gears. Overall, it ran fine, but could not break a tire loose on acceleration. It would return 16-17 mpg on the road.

 

They run long and slow.

If you are willing to search one out and maybe do a little beef, a 300 and AOD could be a good combo depending on your axle ratio.

The article about the C6 being so power thirsty is decades old. It had to do with full throttle, high rpm use--i.e. drag racing. So yes, the C6 wins the power grab contest, but in daily use is probably the same or not much worse than any other non-od, non-lock up automatic.

 

Ok guys thank you !
Just thinking out loud ...
It's a 3/4 ton so I really don't want to compromise its
Capability with an aod.

 

I use one in my '33 ****** (runs 13s on street tires) and my '46 460 pickup. I chose it because I wanted to be able to beat on the ****** without fear of shucking a C4. I intend to use the '46 truck to haul my champ car trailer so I wanted the durability there too.



For me, building in a little more HP to spin the C6 outweighed the possibility fixing weaker transmissions down the road.

 

Roadrash, google an outfit called Level Ten or Level 10; their site is a little confusing so you might just want to phone them. For years they have been selling a rolling-element replacement thrust bearing that significantly reduces the drag of the C-6.

 

My 84 f150 with a c5 is currently in the shop for a c6 swap. Should be done Wednesday so I'll be able to have good info then.
The new 6 is gonna have a little valve body work and now I'll be researching this level ten servo. How difficult is it to install the servo as in does it need to be done before Wednesday or can I delay it without completely having to remove the transmission again? I have zero transmission work experience.

 

Curmudgeon's response - if you want to smoke the tires a lot, race around at high speeds, impress everyone with your manly exhaust that rattles windows from a mile away - it's the wrong combination. If, on the other hand, you don't drive like a jackass, it will keep up nicely with traffic, return decent mileage, do light-truck stuff better than you would think, and you would have one of the world's best engines coupled with a transmission rated for far more horsepower than any normal 300 would dream of producing - it will outlast your grandkids.

 

Well, it doesn't smoke the tires now.
Ha ha
does run well with 355's rear gears not looking for a hot rod .
i've got my Harley for that!
Parts are becoming hard to come by for this thing I'll have to look around for a automatic column.
What about Drive shaft length?

 

Driveshaft will have to be altered. Mine will need shortening.

 

This is info from an old Car Craft Mag publications:

Horsepower loss
Powerglide_____18 hp
TH-350________36 hp
TH-400________44 hp
Ford_C-6______55-60 hp
Ford_C-4______28 hp
Ford_FMX______25 hp
Chrysler_A904__25 hp
Chrysler_727___45 hp

Automatic Transmission Gear Ratio's
GM :
Powerglide...........1.76/1.82 1.000
TH-350................2.52 1.52 1.000
TH-400 (3L80)......2.482 1.482 1.000

Ford:
C-4.....................2.46 1.46 1.00
C-6.....................2.46 1.46 1.00
AOD....................2.40 1.47 1.00 .67
AOD Wide.............2.84 1.55 1.00 .67
AODE/4R70W........2.84 1.55 1.00 .70

 

Those 300's were reliable, I used to own a 1992 and never had a problem with it.

 

It'll run. My dad had a '82 F150 with 300-C6-4x4-3.55 gears. It would chirp a tire off the line if you got into it, then pretty much run out of steam. 3000 rpm down the freeway at 60 mph was less than premium. 12 mpg pretty much no matter how you drove it.

My '94 F150 with 300-E4OD-2wd-3.08 gears is much better going down the road. The overdrive helps a lot. I'm getting 18-20 mpg, mostly highway.

 

I remember those figures.

Good info.

But some readers may get the impression that spinning the transmission at ANY SPEED / LOAD condition will require that much power when, in fact, that was the maximum amount of power required at WOT, high speed. If you're just cruising down the highway at legal speeds your power draw will be on the order of a magnitude less, so as not to be such a great factor. I would be willing to wager that torque converter design / stall speed / size has a much greater effect on fuel consumption that the type of transmission used, especially in high gear (direct drive) where you are not putting any power through the planetaries.

 

I just got my truck back this morning from the c5 to c6 swap and initial response is that I regret the change. The c5 was substantially quicker than the 6. When rolling down the highway it feels about the same Quickness wasn't my reason for the swap but I miss the zip. It does feels stout under there now. Like it will outlive my grandkids and that was the purpose but It is now so sluggish off the line that I'm wondering if my Holley 390 needs to be retuned from a new starting point. Is it common to need a carb tune up after a swap?