The guy I bought my 66 coupe from told me it had a c4. While going down the highway in third gear, I moved it into neutral and it went into a higher drive gear (or so I think). When I looked under the car at home I found a brand new tranny with FOMOCO C6DP-74040 stamped in it (the numbers could be slightly wrong, it was a hard angle to see at). Any one know where to look for info on this? I tried FOMOCO.com, several search engines and they came back with zero matches. Also, this DIF says C70W 4025A 12 (and I have an extra DIF with C70W 4025A 11). Any thoughts on these? Thanks in advance.