FMX to C4 Automatic Transmission

[fangstang]

Hi guys can any one help me I’m going to swap my FMX out for a C4 in my 1972 Grande , my question is I’m wanting to either buy a genuine transmission mount to suit my C4 or see a Picture of the difference between a C4 and a FMX Mount so I can work out how to modify my existing mount to fit the C4 , also any other info you guys have on what modifications are needed to do the swap out obviously I know I’ll need to make another tail shaft and fabricate some new cooler lines , but from what I’m told the T bar from my FMX will bolt straight up to the C4

Sent from my iPhone using Tapatalk

 

[Hemikiller]

You'll need the C-4/MT "4-leg" transmission crossmember

https://images.weserv.nl/?url=i42.tinypic.com%2F33uvrx3.jpg

Insulator is the same for FMX & C-4

Shift rod from shifter to transmission is the same length, but there are minor differences between FMX and C-4. It "should" work - as long as your C-4 is a floor shift model.

You'll also need:

shorter driveshaft (FMX - 51 3/32" - 4 speed/C-4 - 50 13/16") - you might be okay with this, but you'll need the 28 spline C-4 type yoke regardless.

C-4 Cooler lines

Flexplate and block plate to match C-4 transmission.

C-4 backdrive rod to column

 

[fangstang]

You'll need the C-4/MT "4-leg" transmission crossmember

https://images.weserv.nl/?url=i42.tinypic.com%2F33uvrx3.jpg

Insulator is the same for FMX & C-4

Shift rod from shifter to transmission is the same length, but there are minor differences between FMX and C-4. It "should" work - as long as your C-4 is a floor shift model.

You'll also need:

shorter driveshaft (FMX - 51 3/32" - 4 speed/C-4 - 50 13/16") - you might be okay with this, but you'll need the 28 spline C-4 type yoke regardless.

C-4 Cooler lines

Flexplate and block plate to match C-4 transmission.

C-4 backdrive rod to column

Is the length of the tail shaft you gave me correct ? I mean could I make one up ready from the measurements you gave me ? I already have a yoke to suit the C4 and and everything else like flex plate and torque converter

Sent from my iPhone using Tapatalk

 

[fangstang]

Where can I get that 4 leg mount from ?

Sent from my iPhone using Tapatalk

 

[Don C]

There were two transmission lengths for the C4, the pan fill transmission is about 6 inches shorter than the other one, the case fill transmission. The difference in them is that for the pan fill the dipstick connects to the transmission pan, and in the case fill the dipstick tube connects to the side of the transmission case.

The overall pan fill transmission length is 24-5/16", the case fill is 30-19/32", and the FMX is 30-1/4". The case lengths and tailshaft and tailshaft housing lengths are different on the two C4 transmissions. Case fill transmissions were used only on cars. Pan fill were used on pickups and some full size cars.

 

[Hemikiller]

You'll need the C-4/MT "4-leg" transmission crossmember

https://images.weserv.nl/?url=i42.tinypic.com%2F33uvrx3.jpg

Insulator is the same for FMX & C-4

Shift rod from shifter to transmission is the same length, but there are minor differences between FMX and C-4. It "should" work - as long as your C-4 is a floor shift model.

You'll also need:

shorter driveshaft (FMX - 51 3/32" - 4 speed/C-4 - 50 13/16") - you might be okay with this, but you'll need the 28 spline C-4 type yoke regardless.

C-4 Cooler lines

Flexplate and block plate to match C-4 transmission.

C-4 backdrive rod to column

Is the length of the tail shaft you gave me correct ? I mean could I make one up ready from the measurements you gave me ? I already have a yoke to suit the C4 and and everything else like flex plate and torque converter

Sent from my iPhone using Tapatalk

Those numbers came straight from the Ford Master Parts catalog, but you need to verify what you currently have.

 C-4 did not come behind the 351-2V in the 71-73, so the numbers are for the 351-2V cars with the 3 & 4 speed transmissions. C-4 is the same length as those transmissions. Figures are u-joint center to center dimensions of the driveshaft itself. I personally would swap the C-4 yoke onto your current driveshaft and see how much free play you have behind the transmission. You need at least 1/2" before the yoke would bottom out on the trans when car is at ride height.

I'm sure someone here has a spare 4-leg trans xmember, place an ad in the Wanted sections.

 

[Don C]

You might luck out and another forum member that lives in Australia has one they'll sell you.

OMS Don and MotorCity Mike have good supplies of used parts. They are both advertisers and supporters of this forum.

 

[Studdley]

Why would you want to get rid of such a fabulous boat anchor