C6 to 4r70w swap

[73 SGM Mach]

The time has come to begin the 4r70w swap! I'll be putting it in the air shortly so I'm trying to track down all the how to's on this conversion prior to starting. So I need your help finding them all. I tried looking but I cant seem to find all them. I'm looking for the flexplate, cover plate, the actual tranny conversion articles, and recommended driveshaft length and where to purchase everything. I have Joe's conversion kit and the Holley efi tranny control and wiring. Thanks in advance for the help!
Jeff

 

[Sheriff41]

I used CPC products when I did my C6 to AOD conversion twenty-some years ago. Everything worked very well for my conversion. They have a kit with most of the parts (no computer) https://calponycars.com/collections...d-conversion-kit-for-holley-style-carburetors You may want to contact them and see if it applies to the 4R70W.

 

[giantpune]

I'm gearing up for this same conversion. from what I gather, you want to visit your pull-a-part yard and find a transmission out of a 2000-2002 V6 mustang or F150. They have the correct bellhousing and still early enough that they have the provision for a speedometer cable. Grab the yoke with the transmission (hell, grab the whole driveshaft cause they are cheap at the pull-a-part. The transmissions from the larger V6 F150 supposedly already have slightly upgraded guts than the smaller V6. But either one will be able to hold up to a mildly built pushrod motor. Transmissions at the pull-a-part yard run $150 and take about 30 minutes to remove.

If i'm not mistaken, they use the 164 tooth flexplate, block spacer plate, and starter. And the transmission is longer than our stock ones, so the stock driveshaft may be able to be used if you have it shortened. I just get the transmission installed, set the car on the ground, and measure. A local shop can shorten a driveshaft or make one from scratch for half what you'll pay online.

For cooler lines, I have one car with -AN fittings and soft lines running from the transmission to the radiator. I was just gonna do the same for my 4R70W swap.

I'm swapping the whole motor over to a holley terminator max computer that will run the engine and tranmsission.

 

[giantpune]

I got my junk yard 4R70W today. Pulled it out of a 1998 E-150 van with a 4.2. The vans have an insanely long dipstick and tube. I'll have to go back to the yard to snag a shorter one. Or I may go with the flexible one from lokar to make sure it fits in our car and around my exhaust and everything. The van also has a long driveshaft that looks aluminum and has the correct yoke and u-joint at one end. If you have a local shop, that would be a good donor to be shortened.

This transmission bolt pattern matches the block separator plate I had laying around that was between my 351C and a C6.

 

[73 SGM Mach]

Does anyone know the correct length for the driveshaft for the 4r70w connected to a 9 inch rear?

 

[giantpune]

For a dipstick, I looked at a few different cars at the junk yard. The shortest one I saw was in the 4.6L crown vics and all their sister cars. I walked around till I found one somebody else had already taken the intake manifold off. That made it easy to remove the lone 13mm bolt that holds it in place and lift it right out the top. The dipstick lines up perfectly with my V6 4R70W.

I have a feeling the best answer for how long of a driveshaft is gonna be install your transmission, set the car down so the weight is on it, then measure. There may be some variation from one guy's back yard installation to the next.

 

[basstrix]

Does anyone know the correct length for the driveshaft for the 4r70w connected to a 9 inch rear?

Here's a dimension chart I snagged....probably from here...sorry, can't recall who posted it, otherwise, I'd give them credit for it. It doesn't provide the driveshaft length, but perhaps you can derive from other known dims?

 

[giantpune]

Here's a dimension chart I snagged....probably from here...sorry, can't recall who posted it, otherwise, I'd give them credit for it. It doesn't provide the driveshaft length, but perhaps you can derive from other known dims?

I don't think that chart covers everything. There are different length 4R70W tailshaft housings and output shafts.




I got my donor cleaned up enough to read some part numbers. My output shaft housing is part RF-F3UP-7A040-AA. Here it is next to the 1973 C6. The 4R70W looks about 1.5" shorter and the rear mount holes are an inch or so rearward.

 

[mrgmhale]

I don't think that chart covers everything. There are different length 4R70W tailshaft housings and output shafts.




I got my donor cleaned up enough to read some part numbers. My output shaft housing is part RF-F3UP-7A040-AA. Here it is next to the 1973 C6. The 4R70W looks about 1.5" shorter and the rear mount holes are an inch or so rearward.

View attachment 96791

View attachment 96792

Re: different length tailshaft housings, the AOD I got from Monster Transmission for our 1973 Mach 1 came out of an F-150 with 4WD, which meant it had the short tailshaft housing. It turned out it made the overall length of the AOD only 1/4" longer than the original C4. Looking the input slip yoke's wear patter I had plenty od excess travel to use the proginal C4 driveshaft, unchanged in length or yoke. It fit perfectly and I still have about 3/32" of additional travel if it ever needs it - doubtful it will.