Hello everyone! I'm finally apart of the FTE Forums . I've come here to obtain wisdom for my build.


About 2 years ago I bought a '68 F100 Custom Cab...for 400$. No rust whatsoever, no dents, no nothing! I've built a motor for it, but I'm stumped on what transmission I should use.. The motor I'm using is a 1987 300 inline 6 with a few mods. Headmen Headers, Offy DP 4bbl intake, Holley 390 carb, Lunati Voodoo 268 cam (I know....BIG!), and an HEI Distributor. Not sure if any of those specs really help, but whenever I talk about the build I HAVE to mention the motor. Makes me warm and fuzzy inside . Now on to the actual topic...what tranny should I use?! The rear end is a nice 3.73, which makes me really want to throw in an OD of some sort. I got a C4 laying around, but is the GearVendors unit really worth it compared to the aftermarket AODs I can buy? What about an E4OD? Not sure what to do here. Any suggestions would help! Thanks!

Edit: I plan on building this to get somewhat decent mileage.

 

'88 to '93 AOD with some beef up parts.

Serving suggestion.

 

Gear vendors are weak links and severely over hyped. I have blown the cone clutch on several units and am done with them. There is no good use of a overdrive on a transmission that doesn't have a lock up converter. There is so many good OD transmissions available for the SBF. The AOD is not my favorite but it is the cheapest choice. If I were doing one I would do a 6R80 and a controller. Super cheap used and they are durable and have a super deep first gear.

 

6R80 and a controller all day long...if you are gonna swap, do it well!

 

That's what I thought, too.... there's many people in my area with older cars running a C4, but no one with Gearvendors. Comparing prices, WOW! I'd save around 1,000$ buying an AOD from Monster Trans over a Gearvendors!

 

I'm going to suggest meeting in the middle with the 4R70W. I run one in my 447FE F-250 and it performs well. It has some upgrades, mostly from Sonnax but is fairly stock. The 98 to approximately 2003 V6 Mustang and V6 truck units will bolt up to your engine without an adaptor. The W means wide ratio which is great for a truck. The 98 and up units are much stronger than the AOD's. An AOD can be beefed up but you'll likely spend more on upgrade parts than you would on a USShift controller plus you don't have to mess with the TV cable. I have heard from some people that AOD upgrade parts are getting harder to find as the industry has moved past them. If you limit your search to 98 to 03 you will still have a speedo gear. You have to check closely because right around 2002 and 2003 they started to eliminate the speedo gears on the output shaft. You may need to slightly modify the bottom of the firewall/front tunnel area depending on where the transmission sits. You will have to move the rear transmission crossmember and may need a different mount. Because Ford was messing around with different u-joint patterns in this era you may or may not need an output slip yoke. They are available from several sources if you not able to easily mate the factory slip yoke to your driveshaft. Because the transmission is longer you will need to shorten/modify your driveshaft. Relatively easy to do if you keep your engine/transmission angles near stock.

You will also need a way to shift it. I was able to make a bell-crank mounted to the mod motor version (I had to get an adapter anyway for the FE) that uses the factory shifter. There are several different case designs so you may find that it will be easier to go with an aftermarket floor shifter and cable setup.

To make the 4R70W swap sound a little more attractive, I am swapping my Holley Sniper over to the Holley Terminator X Max so I can control the EFI and trans out of one box. I'll be selling my USShift (Baumann) controller and can make you a sweet deal for the controller, wiring harness, and a rod actuated throttle position sensor. Send me a message if interested.

The 6R80 will most likely need a block converter and the USShift controller for the 6 speed is quite a bit more. The gearing is set up for modern high HP relatively low torque motors and with your 3.73 gears you may find the first few gears to be unusable.

I guess with all that is required to do a swap, the gear vendors starts to sound more attractive but they aren't cheap either. I can pull 4R70W's out of the local pick and pull for $100 and most need very little work if any.

 

Any idea what caused the failures? Did you have high power in front or heavy weight behind? I ask because I've had a gv for a couple years in my '65 and really like it. I do mostly interstate. Years ago (before installing the gv) I used this truck to pull a camper but not so much anymore. Now its hardest chore is hauling some firewood.

I'm asking hoping I can avoid whatever caused your problems. Thanks

 

AOD if you want a cruiser.

But you may find that the AOD overdrive is too high of a gear. Depending on how tall your tires are, 3.73 is going to be on the verge.

I run 4.11 gears behind the AOD in my F100, and it's perfect for 31" tires.

My bronco is getting 4.56 gears in place of the factory 3.55.

You're probably thinking " Holy cow those are low gears! How do you drive down the highway?" Well yes, they are low gears, but the 0.67 overdrive ratio turns them into 2.75, and 3.05 final ratios.

Perfect for cruising.

 

I run a gear vendors/C4 combo in my mustang with 4.11 gears. I can't speak to the long term reliability under towing circumstances because that's not what I'm doing, but so far it's taken a tremendous amount of abuse and held up very well on the drag strip. Having 6 gears instead of 3 makes a huge difference, and if you factor in the conversion costs of doing an AOD swap (TV cable, cross member, torque converter, etc.), it's not that much more expensive.

 

Since you brought it up, i'd like to point it out The facts, speaking from personal experience with a few of these transmissions and swaps.

-the Lokar TV cable is $98. (I just bought one)
-Crossmember is the same. What's the cost of drilling two holes?
-driveshaft is the same length with a C4,
-torque converter was $80 when I bought mine five or six years ago. I imagine they're probably a little bit more now.

Just last week, I had an AOD rebuilt at a local shop, for $1500. That included some hard parts and a new converter. A soft rebuild would've been cheaper, but this particular transmission had some pretty big problems.

A used AOD in working condition it's about $300-$400 in my experience. Unknown condition (cores) sell for about 100 or 150. Maybe less.

Soooo, an AOD swap can cost as little as $500, or it can be 1800+. It just depends on what you start with.

 

Yes shifting under WOT killed them.

 

Okee doke. Thanks for the info.