How do you guys feel about a 300 6 with a c6 transmission and 9" rear with 2.75 gears?

 

Swap the C6 for a T18 with grany first that is what my 81 flare side has.
Now I have not had on th we road so can't say how it does but that was a combo Ford put in a lot of trucks would be my guess.
Dave - - -

 

Great highway truck that can keep up with traffic without sounding like it's going to blow up. The slip of the c6 convertor should get it going ok with those gears also. It's one of the better combos for fuel mileage till the overdrive trannies became more common.

 

The only thing wrong with the C6 is it is a power hungry hog.
It takes a lot more power to turn it than the C4 auto but it is a HD auto and it is used it a lot bigger trucks and cars with big block power plants.
I had one in a 76 E350 van with a 460 and on weekend pulled a 2 car trailer to / from races, went thru 2 motors no tranys.
Dave ----

 

The C4 is a plenty strong tranny, especially behind a 300.

 

I ran a little built up C4 behind a built up 302 with 351 heads in a 66 Bronco used for off road racing.
Lets say the stock front axle did not live long with that set up in sand drags and the front wheels were hardly on the ground.
I would say a C4 would also work in a street pickup.
Dave ----

 

Exactly. I'd be fine with a C4 past 500 hp, easy

 

the combination you have listed would be darn near unbreakable. Not enough power to break anything and should last about forever. Might not be good at hauling bed full of brick or stone or shingles or something, but for the occasional couch or refrigerator or washer/dryer, you'll be fine!

 

I did some reading. Well, lots of reading. And for the 300 6, C6 and the 9" rear. Mostly all nice things. All have been said to be pretty well bulletproof. Found a site that sells rear ends and parts. Their calculator showed with my gear ratio and stock tires that 2000 rpms is right about 56.75 mph. So I figure driving at 55-60 is pretty well in the fuel efficiency sweet spot.