I plan on buying a 1977 F150 4x4 SWB with a 351 and a 4 speed.

What can i pull a C6 out of that comes with an overdrive from factory that will bolt directly up?

Thank You
Josh

 

Nothing. C6 was never overdrive. I believe you would need to go to a E4OD or 4R100 and then deal with electronic shift control.

 

Check out gear vendors web site they have ALL kinds of overdrives. The only problem I can see is that they are VERY pricey. Popa John

 

Okay this is what i'm going to be doing and i want a STRONG Automatic transmission with an OD for highway purposes: Basically i want a rig that i can drive on the highway/4-Wheel and get decent MPG, i know these trucks get horrible MPG but i want to get the better of what they do get. I'm going to be running 33x12.50 and 3.50 gears with Detroit Trutracs. Is the e4OD and 4r100 stock trannys? Oh and eventually i'm going to be putting a 6BT cummins in front of the tranny as well so i want something that can handle that engine.

 

I think you'd be better off looking at the Gear Vendors OD unit. You won't have to worry about it "holding" up. They are known to be bullet proof and also they make all kinds of adapters specific to application to be a pretty much bolt in deal. You'd be able to keep the C6 which is a very good transmission. The OD units are expensive, but you'd be better off in the long run. By the time you get and E40D or equivalent set up in your truck, you may not be far off the Gear Vendors. A good E40D isn't cheap either and you'd need to buy the electronic controller.

 

You wouldn't happen to know the torque rating of the C6 would you. I think i probably will go with the gear venders OD, because to be honest i love the C6 trannys and always have.

 

Quick Google search came up with this site listing torque values for their rebuilds:
C4 C6 Performance Transmission from PATC, C6 Transmission Level 3 Sure their are plenty more or better sites.

 

Guys, you can't have your cake and eat it, too. C6 isn't available anywhere with an overdrive but it can be built up bulletproof.

If you require a stupid strong auto trans with overdrive, you will have to run an AOD-E (which will have to be custom built 'cause they're not all that strong) or a 4R100. The latter is rock solid and has an excellent final gearing ratio for highway MPG. You can get them cheap now that they've been shipping on StupidDuty platforms (Excursion included) for years. The major drawback is that you will have to buy a shift controller from the aftermarket folks. They're pricey but you obviously can't expect an engine that was designed for vacuum controlled transmissions to run a computer controlled transmission.

On the bright side, you'll get complete control of your shift points. That, plus the 1.00 OD ratio, plus the extra gear, plus the all-Ford hardware all adds up to why I want to run the 4R100 myself eventually in the '78 Bronco.

Or you can go to the dark side and install an Allison.

 

Not all OD trannies require an electric shift controller! I bought non electric OD unit for my '64 from these guys AOD Transmission from PATC, AOD Transmissions My '64 was built to drag race with, with a fastest time of 11.774 @ 114.4 mph in the quarter in a 4000 pound all steel truck. The tranny was never a problem. You call them, tell them what you want and they build it. Cost was very very comparable to a built up C-6. I did have to buy an adapter kit to mount the tranny to my 428, but it wasn't very expensive either

 

I did overlook the AOD, but it's still a 3+ trans and the bellhousing requires a flexplate adapter. The 4R100 is a 4+ trans and bolts straight up to the 335-series engines (and the OP here has a 351, according to his first post).

You can certainly go either way, but for the combination of simplicity (despite the need for a shift programmer), durability, availability and ease of installation I'd still recommend the 4R100.

 

The Gear Vendors would be a super strong way to go, but, on a 4x4 application they bolt to the back of the transfer case so in the case of your SWB truck you would end up with a VERY short driveshaft on a VERY steep angle. This may not be a problem but I think it would be worth looking into.
David.

 

Exactly why I found myself digging into transmission options in the first place... I have a '78 Bronco so every inch in drivetrain length is a liability. The GV OD is a great product by all accounts, but look at this:



Where the hell does that fit on a short wheelbase 4-wheel drive truck?

 

Fortunately, on a 4x4, the transfer case fits in where that adapter fits. The adapter is that long to take the place of the tailshaft of a 2WD vehicle, so, on a 4x4 you will probably be about the same length, but unfortunately, on a SWB 4x4, it will probably still be too long.
I feel your pain as I have a 79 SWB 4x4 that I want overdrive on but I also have a perfectly good working C6. Oh well, have a couple other projects to finish first so that decision is a while off yet.
David.

 

[quote=speedyweasel;11427147]Exactly why I found myself digging into transmission options in the first place... I have a '78 Bronco so every inch in drivetrain length is a liability. The GV OD is a great product by all accounts, but look at this:



Where the hell does that fit on a short wheelbase 4-wheel drive truck? [gear vendors makes a shorty version for that purpose. check their website)

 

check gear vendors for their short version. it might work for you.