i have a 1969 mustang fastback that came from factory with 6cyl.I have a rebuilt 351m in a 1977 ford f150 I would like to install in the mustang untill i finish building the 302 that came with the car ( wasn't installed).has anyone done this and if so what problems did you run into! thanks
first off, it won't work unless you plan on doing some pretty serious fabrication on motor mounts. there is not a stock or even aftermarket motor mount that will adapt a 351m/400 into an early stang. you will also have to use a different transmission, as the 351m/400 uses a 429/460 bellhousing bolt pattern. IMO, i'd just wait until the 302 is finished
One more thing to add----- changing spark plugs will be damn near impossible too with a 351M in a 67-70 Stangs engine bay. Tried the fit with a 400 once in a 67 Stang, same block/heads as a 351M, Couldn't access the spark plugs at all.
I had a 1970 mustang 15 years ago that had a 351m in it - I did not put it in myself but it fit well and gave no problems - I have no idea what mounts were used
thanks to all for the info . I had a feeling it wasn't going to work without major work. I guess plan b will work sell the truck and use that money to finish the 302. again thanks