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.

 

[73 SGM Mach]

You will need a 164 tooth flexplate in the balance of your engine...be it 28/50/0 and you can and should use a 2000 explorer 5.0 small starter. you will also need the engine block plate and the 71-73 cars will need a 50.5 inch driveshaft, have and aluminum one built(trust me on that), and the slip yoke must be for a 4r70w. most ford trans are the same 28 spline but the 4r yoke has a larger od and must be used.
@InjectedMach
Wrote the above. Here is my questions. I read somewhere the 1973 351c has a 164 tooth flexplate. If this is not correct what is the balance on the 351c so I can order the correct flexplate? Is it 28 oz?
Next is the engine block plate. I also read the 351c block plate will work. Please confirm correct fit.
Joe wrote that we will need a 50.5 inch driveshaft. I'm just trying to firm up all the parts needed. Thanks all!

 

[73 SGM Mach]

Also I found this write up for a 65 vert 302 with C4 changeing to a 4r70w. I found it a very useful read for someone who hasnt done this yet.
https://www.vintage-mustang.com/thr...uide-into-a-1965-mustang-convertible.1203917/

 

[InjectedMach]

You will need a 164 tooth flexplate in the balance of your engine...be it 28/50/0 and you can and should use a 2000 explorer 5.0 small starter. you will also need the engine block plate and the 71-73 cars will need a 50.5 inch driveshaft, have and aluminum one built(trust me on that), and the slip yoke must be for a 4r70w. most ford trans are the same 28 spline but the 4r yoke has a larger od and must be used.
@InjectedMach
Wrote the above. Here is my questions. I read somewhere the 1973 351c has a 164 tooth flexplate. If this is not correct what is the balance on the 351c so I can order the correct flexplate? Is it 28 oz?
Next is the engine block plate. I also read the 351c block plate will work. Please confirm correct fit.
Joe wrote that we will need a 50.5 inch driveshaft. I'm just trying to firm up all the parts needed. Thanks al

You will need a 164 tooth flexplate in the balance of your engine...be it 28/50/0 and you can and should use a 2000 explorer 5.0 small starter. you will also need the engine block plate and the 71-73 cars will need a 50.5 inch driveshaft, have and aluminum one built(trust me on that), and the slip yoke must be for a 4r70w. most ford trans are the same 28 spline but the 4r yoke has a larger od and must be used.
@InjectedMach
Wrote the above. Here is my questions. I read somewhere the 1973 351c has a 164 tooth flexplate. If this is not correct what is the balance on the 351c so I can order the correct flexplate? Is it 28 oz?
Next is the engine block plate. I also read the 351c block plate will work. Please confirm correct fit.
Joe wrote that we will need a 50.5 inch driveshaft. I'm just trying to firm up all the parts needed. Thanks all!

Hello 73 SGM Mach,
A 73 351C is 28 oz . A 164 tooth plate is a different diameter than a 157 or it has been my experience anyway hence the blockplate for starter location.. If you have a 9" standard length yoke then a 50 to 50.5 inch driveshaft is the ticket.

 

[giantpune]

Yes, the old small block fords used a 28oz balance, 164 tooth flexplate. The block separator plate and the flexplate from a 70s 351C/302/351W would be correct. With the caveat that the bold pattern on the flexplate matches your torque converter. When you go shopping for a 4R70W torque converter, there are several different bolt patterns. Whatever one you pick, your flexplate has to support. Some flexplates have 3 different bolt patterns to allow you flexibility.

The torque converter that came in my junk yard 1998 4R70W happens to use the same 11.4" bolt circle as the flexplate from my 351C/C6 combo. If I were doing a budget build, I could use the same flexplate and whatnot that's been attached to that engine since somebody at ford installed it 50yr ago. Just unbolt the C6, and lift up the 4R70W in its place.

But I've had cracked flexplates before. Now's the time to replace this old one. Its been getting beat up on since my mom was a kid. And if you're replacing that, you are not supposed to reuse the flexplate mounting bolts.

 

[73 SGM Mach]

https://www.summitracing.com/parts/SUM-G111SFI#overview
I need to verify the bolt pattern on the torque converter but hopefully this works?
What about the engine block plate?

 

[giantpune]

What about the engine block plate?

Thats the same part as the block separator plate i mentioned above. The original one from our cars have the correct holes and starter location for a 164 tooth flexplate.

For the starter, I was planning on using one out of a truck. My 1996 F150 has a 5.0 and a 4R70W. Even up through 1996, you could order a F150 with a 5.8 (351W) and both C6 and 4R70W were some of the transmission options. When shopping for starters, there are more options for the F150 and they are generally cheaper than a 2000 explorer.