dblizzo 10 Report post Posted May 29, 2018 For my 69, I just got my new C6 transmission from tci. Im switching from an old fmx. It looks like the transmission is about 5” longer. For those who have made the conversion, what else do I need to get to make this switch? I know I need a new dipstick. Driveshaft? I have an auto, linkage? Any help would be appreciated. Thanks Quote Share this post Link to post Share on other sites
dblizzo 10 Report post Posted May 30, 2018 So I guess this isnt a popular choice? Ive tried looking at old posts on this and other fourums, but they didnt provide enough help. Most of what Ive seen is guys taking an old C6, sometimes from a steering wheel type shifter, and trying to make it work with a floor mounted shifter. This C6 is new from tci and wonder if they made them to fit. Probably not but its got to work now. Can you shorten the drive shaft or do I have to buy a new one? The linkage from shifter to trans seems like from what I read will not work unless modified. Do they sell an aftermarket one? If so I cant seem to find one. Quote Share this post Link to post Share on other sites
1969_Mach1 333 Report post Posted May 31, 2018 Two people in my area made that switch FMX to C6. Both were 69 Mach 1's. Both had 351C motors swapped into them as well. Athough a long time ago, neither one had any issues to sort through. As best I remember both simply used parts for a 1970 Mustang with a 351C and a C6. Drive shafts can easily be shortened. Have is rebalanced after shortening to be safe. As long as your trans has the shift lever for a floor shift car, shift linkage should not be an issue. The shift linkage on your C6 should be basically in the same orientation as the old FMX. If not, it is probably setup for a column shift. If that is the case, not all is lost, it should be fairly simple to swap out the shift lever on the trans. I've removed them on other cars to replace the shift shaft seal that's in there. Quote Share this post Link to post Share on other sites
dblizzo 10 Report post Posted May 31, 2018 Thanks. Quote Share this post Link to post Share on other sites
1969_Mach1 333 Report post Posted May 31, 2018 Yeah, that was about all I offer on this topic. It shouldn't be too bad of a swap. Somebody here probably knows more details. If you get in a situation needing a part and not certain what exactly to get, I'd call Perogie Enterprises. They know these cars pretty well and have helped me when I want used original or NOS parts. They can be pricey on rare parts. But they seem to be fair on the common stuff. Quote Share this post Link to post Share on other sites
Ridge Runner 1,113 Report post Posted May 31, 2018 I had a small case c6 behind a 302 in my old 70 . Not a problem . Mine was from a ford van and had the shift leaver upside down ,i simply bolted another leaver to the column shift leaver so i didnt have to open it up . I had to shorten the drive shaft . I did like the swap and it worked perfectly . I did change the tranny mount to the C6 mount ,i may have a couple here some where still Quote Share this post Link to post Share on other sites
mqu02 30 Report post Posted May 31, 2018 The C6 fills up the tunnel pretty well, so I would make sure you get something close to factory cooling lines, because they hug the transmission really tight. This also includes the special 90-degree elbow that has a nut that helps you orient it correctly to the transmission while sealing. You will find that there is a lot less clearance for a C6 than a C4 or FMX in the tunnel. Also, your shift linkage will probably take some custom fabricating. The easy solution is to get a big block shift rod with the correct shift lever (which is available from Mansfield Mustang), but that will require that you drop the pan & valve body to install. If you don't want to do that, something similar to what Ridge Runner posted will be required, however you will probably need to determine the length by trial & error (if the length isn't right, you won't get into the gears correctly). Quote Share this post Link to post Share on other sites
Ridge Runner 1,113 Report post Posted May 31, 2018 Determin the heigth of the shift leaver from the old tramsmission and make the bolt on leaver the same ,if i remember right i made the shift rod from 3/8 rod and threaded both ends and used heim joints ,its been a while Quote Share this post Link to post Share on other sites
Ridge Runner 1,113 Report post Posted May 31, 2018 Yes i did use heim joints ,and i slotted the top eye on the bolt on shift leaver ,the heim could be raised or lowered so the leaver would shift in sink with the shifter Quote Share this post Link to post Share on other sites
dblizzo 10 Report post Posted May 31, 2018 Thanks for the helpful info guys! I'm hoping to get this thing put in this weekend (along with the engine) and of course I'll find out more then. Quote Share this post Link to post Share on other sites
