I am looking to replace the burnt c6 that is was in my truck. I have no clue, besides what i have read in here, how to do much to a transmission besides drain and change the fluid ,so a rebuild is out of the question.

Currently I am runnin a c4 that someone traded me for lawn work (what i use the truck for), but it has started slipping so ill need to replace it anyway.

Now to pick yalls brains a little. I really want to have a strait geared transmission. Also I regularly pull around 11000 lbs with this truck. I know that due to the use of the torque converter, an automatic pulls better, but a manual would elimanate the "gear hunting" on hills.

Some info on the truck now. I have a brand new 351w that is going into the truck. This motor was dyno tested to be 550 hp at 6500 rpm. I would really like to have a transmission that can use that power for pulling reliably rather than showing off.

Now, what transmissions would yall recommend for me?? and how much would it cost??

 

A C6 is a really tough, strong transmission if it is built right and would do the job behind
that 351. You could also get a built AOD type which is also really strong if built right.
The only extra issue with an AOD type is making sure you can correctly hook up a TV
cable from the carb/fuel inj. to the transmission.

 

ok, so... what is going to be required to make a c6 work with this engine?

And as for the AOD, well its got duel 4bbl edelbrock carbs, so i have no clue how the TV would hook up. Also I have no need for the OD gear, and the simplier i can keep it the better.

 

I am confused. What truck are you working on? The one in your signature? It's listed as having a t18.

 

thats a last resort. I was lookin at a parts truck that has a T18. Id keep the C6 if it is cost effective. Otherwise im getting the T18

 

I used to like the c6, it is a good tranny. It's all I ever had in the trucks I have used for towing till I changed to the zf in my diesel. I now like the manual better for towing.

The reason is the brakes on these trucks stink. Anyone who has done any towing with Fords and compared them to other brands, will confirm this. They get the job done, but don't inspire any confidence that you could bring the speed down quickly during a panic stop like the brakes on other trucks can. The manual tranny won't help in panic stops, but it does help on long down hill grades to keep the speed under control. Sure, you can downshift the c6 and it helps, but it doesn't control the truck like a manual tranny does.

I would also recommend a manual tranny for you, if you really are going to put some wild engine in like you mentioned. A race engine like that is not made for heavy towing, but you may be able to make it work if the gearing is really high(4.88 like you mentioned) and you have a manual tranny. You could make the c6 work also, but you will need to use a higher stall convertor, so the engine can wind up a little bit more. That engine will make it's power in the higher rpm range.

 

I see c6's on craigslist for $100 every once in a while that "worked when pulled". If you're trying to do it cheap you could go that route or just have your old one rebuilt, if you shop around you should be able to get it done pretty cheap.

 

Ok, brakes aint an issue. When i do the axle swap this weekend, im also taking a 2.5 ton hydroboost system from a GMC 6x6. The way I see it, if it will stop a fully loaded 6x6, it should be able to stop my 3 ton truck and my trailer.

As for gears, they are gunna have to be high. Ive seen some 4.88's, I may even go to a 5.13 set. Either way, it should keep it up above 2500 RPM, where this engine starts to make its power.

 

Franklin's right... our brakes stink! I don't see hydroboost fixing a **** poor caliper design and outdated drums in the rear. I pulled my 18' 14k lb (that's gross, it was empty) home today and even with only 2 of the 4 trailer brakes working it stops better with the trailer than without (I really need to fix that). Good trailer brakes and controller are a must when you are pulling heavy loads.

 

What model was the GMC?

 

There are a lot of people who do swap in the Ford hydro-boost system off a later f450, and they do seem to have some improvement. More line pressure I believe, since most who install it find they are blowing holes in their old brake lines till they get everything replaced so it will hold the higher pressure.

 

I pulled the axles (complete with the brakes) out of a '44 GMC CCKW-353. The hydro-boost is off of a '92 Kodiac (GM 2 tonner). What you failed to see is that the whole system from hydro to the lugnuts is GMC 2.5 ton. It will stop anything ill throw at it.

 

CCKW-353 (1944), it had all three axles replaced with a newer rockwell unit in 1997, along with a hydroboost off of a '92 Kodiac truck. The only reason that I am parting it out is cause its been sitting so long that the engine locked up, and i cant find the parts to fix it to origional.