FMX-2-C6? Whats needed to convert?

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Joined
Dec 21, 2013
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Location
Brier, Washington
My Car
1972 Fastback (Factory sprint, but now a bright red Mach 1)
351c 2v(big ol cam, holley dominator intake, roller set, edelbrock 4bbl)

fmx
The FMX in the stang is pretty well used (sloppy, sloppy shifts, slips in park, only runs in 3rd sometimes etc.)...

Yesterday I found a guy on CL that does custom work on mustangs and today he sold me a '65 FMX and its green torque converter along with a '73 smallblock C6 for $80 package deal. He said that they worked when pulled about 4 years ago. From what i've read, C6 is preferred over FMX so I'm leaning towards popping in the C6 when the trans in the car finally dies.

What will I need to convert a car that was once FMX to a C6 besides a torque converter and a cross-member? Are the dimensions even the same or will i need a driveshaft?

The FMX I picked up is from 65 and it was originally mated to a 390 so i'd need the bellhousing off of the current trans. I understand that the earlier FMX is different regarding the dipstick, but what else??

What are your opinions on what i should do and how to go about it?

THANKS GUYS!!!!:p

 
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I went fmx to c6. I did not have to mess with the cross member. (73 with a 351c)

I did have to mess with the shifter linkage. Turns out not all c6 had the same linkage. Column vs floor was part of it. The linkage part on the transmission can be swapped out but you do that when the transmission is apart. I modified what I had and 'made' it work.

I had to have the drive shaft modified. I 'think' it was shortened but it was back when Reagan was President so I don't remember exactly.

The cooler lines are different, I bought some after market lines to make it work.

The kick down is also different, I just left it off. Never bothered the transmission that I didn't have a kick down but, of course, it doesn't kick down on it's own. My current carb setup wouldn't support a kick down anyways. But I might look at getting the 'correct' shift linkage next time I rebuild. Mine modified linkage works but it seems like it takes out bushings sooner than it should.

 
I could be wrong but didn't the FMX come out in 1969 ?

In the Marti book all 67 and 68 390's had a C6 or 4 speed

No mention of FMX until 1969 and then only on 351's and

very few 302's.

Look at the casting date code on the trans or the dip stick if it is there.

Pretty much everything Will said on the C6 conversion

biggest issue would be if it is a floor shift trans

other things

dip stick and tube

inspection plate

I thought the FMX vs. C6 cross members had a height difference ?

Next issue - they have been sitting for four years - valve bodies are probably stuck and at the least should be pulled and cleaned up.

Your going to put time and money in a trans that is " suppose " to be good.

 
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Should be a C6 if it came of a 390. I would have the tranny serviced before putting it in as Don suggested much easier to find out if it works before you go and put it in your car

 
I'm not that well versed in automatics, but weren't the earlier three-speed autos called Ford-o-matics? I just pulled one out of a Galaxie and I think they could be mistaken or confused (FMX similar to Ford-omatic)?

A C6 is immediately recognizable due to the integral bellhousing. I think the F-o-M had a separate iron bellhousing, and such could be behind a SB or FE...

I may be way off here, as I haven't messed with them much.

 
The Ford-O-Matics were a 2-speed transmission and pretty much a boat anchor, and was produced from 1959 to 1964, and mostly used with 6-cylnder engines.

The FMX was part of the Cruise-O-Matic series of Ford automatics. The first one in the series was a small case and was produced from 1951 to 1966. The second one in the series was a medium sized case and was produced from 1955 to 1968. The FMX was the third and last in the series, had the largest case, and was produced from 1967 to 1979.

The C-4 was produced from 1964 until 1982, when it was converted to the C-5 with a lock-up torque converter, and production ended in 1986.

The C-6 was produced from 1966 to 1989 and had 3 different bellhousing configurations, small block, FE, and 335-series.

 
you may also want to check the flywheel I switched from a c4 to a fmx and the offset for the torque converter was to deep and it burned the pump out of the fmx the bolt pattern and everything else was the same though

 
Ok, my bad on the 390, again, dont really know. Thats interesting that it could be a F-o-M. I wouldnt think that.

Anybody know any identification features to decide if it is in fast a Ford-o-Matic? The casting says C-5 for '65.

Better find out if the C6 works...

OK so heres my conversion list so far:

-crossmember

-driveshaft (maybe)

-shift linkage (maybe)

-Torque converter

-cooling lines

-what type fluid?

-is anything different regarding starter motor?

Thanks!!

 
Going to the C6 - drive shaft and all 3 linkages are for sures - not maybe's.

 
That's a bit of effort and still not have overdrive.... I'd go aod...
I got the C6 for 40 bucks. This is a buget deal for me. And I dont know anything about that kind of swap. I mean if an AOD rig is cheap too, let me know how to do one!:D

 
Yeah, I realised before that you got the deal real cheap which may be the main reason why you're even doing it considering the fmx may still go a while longer...

After pulling mine 3 times for maintenance, I swore, the next time I have to do it, it'll either be a manual or auto but will definitely have OD.

 
The C-6 was produced from 1966 to 1989 and had 3 different bellhousing configurations, small block, FE, and 335-series.
Don, that should read 385 series not 335 series. 335 series is same as small block.

What the "other" trans the OP is referencing is probably an MX trans which was a precursor to the FMX.

 
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