The original owner just took a hammer to one spot, to enlarge it. But we are going to make it bigger because there is some vibration.
I replaced a C4 in a Torino once with an FMX... I remember it being fairly easy. The driveshaft fit fine. It needed it's own converter, bellhousing, and flexplate. The tranny mount might be a little further back than the C4, I don't remember. The Torino, unlike the Mav, had a universal tranny crossmember. I remember it had 3 locations... front for C4 and rear for C6, I think the middle is the one I used on the FMX, so it might not be a direct bolt in for a Mav crossmember. Some things to consider: FMX performance parts are like 'hen's teeth', very hard to find. The tranny is cast iron and weighs a ton. It absorbs more HP to function than a C4. The tranny was designed and unchanged since the 1950s. It's original name was 'Cruis-o-matic'. Dave
Aren't the later models (mid to late 60s) FMX all aluminum? Still heavy as hell, but I don't think they're cast iron. I'm pretty sure my old 55 has the early FMX, all cast iron... never seen a tranny rust until I got that car...
FMX swap I know this thread is old but.... I put an FMX in my maverick temporarily until my AOD is ready. the tranny cross mamber will work but it is VERY tight. The FMX is larger in diameter and mine is actually touching the trans tunnel. I am running a 289 and I can definitly tell theres a performance drop. In fairness it could be a crappy torque converter. There are 2 FMX's... FX which is the small shaft. ( fits the maverick driveshaft yoke) and the MX with the large shaft ( doesn't fit maverick drive shaft yoke ).. The FMX is a solid trans that will hold up under some punishment but performance parts are difficult to find. If I wasn't going with AOD I would go to a parts yard and buy a C5 and swap the bellhousing, torque converter and valve body from a C4.. Just my opinion but I hope this helps someone in the future..