My 460 C6 will not go into my 66 F100 right now and here's why: the C6 touches the cab at the tranny tunnel and will not go back far enough to allow the 460 to sit on its mounts. Now, I could move the 460 forward (bad idea) so everything would fit, but I decided to do some research and I found that grandpa had his truck repaired by someone who replaced the cab mount metal (probably my dad). When he did this, the cab had already sunk an inch or so and now it has new "custom" cab mounts that allow the cab to sit lower... just low enough that I can't get the engine and transmission to sit peacefully where they should. The old 3 speed was fine however the C6 is dimensionally unable to slide into the same spot. At the present time, I lack the space, time, financial resources and the feminine approval to begin the process of replacing that which rust and previous repairs have taken.

Here's where the question starts: Fordboypete said something about a C5 being similar to a C4 and found in many trucks. A transmission that has a removable bellhousing and no giant case in the way is all i would need to buy enough time to get the truck running, make the wife happy and start assembling parts to put this truck back up where it belongs. Is a C5 smaller where the bellhousing meets the body of the transmission? Where can I find a 351M or 400M C5? and Is the C5 strong enough to withstand the extra torque of a very mild 460? Anybody got any suggestions?
thanks a lot

 

As a side question: Is it even possible to remove a C6 from these trucks without taking out the transmission? It seems like that crossmember directly under the bellhousing is going to prevent the transmission from dropping out and it is rivited on. I dont know, I was just curious.

 

Remove the cab mount bolts and raise the cab an inch or two. Use hardwood for the spacers. The crossmember on automatic trucks is bolted. If you have a truck that was originally a three speed the crossmember is riveted. Cut the rivets, replace with bolts.

 

You may want to check to see if the frame mounts are in the right location
there are many holes to chose from . If your in doubt as were there located
you can look at a (73-79) that has a 460-429 already installed to see were
they should go . Also you said the cab had custom cab mounts you might add
shims under the mounts to get back where it goes .





P.S. when I refer to frame mounts some people call these engine stands.