1992 F150 460 engine swap

I have a 1992 F150 that I want to put in a 460 and C6 Automatic. I need to k now if the motor frame mounts from a F250/350 will permit the engine to fit. In another words, are the frame rails the same distance apart between the F150 and the F250/350?
I have heard that L and L Truck of Texas has every thing I need. However I don't know the city in Texas.
Can anyone lend some assistance here?

Sincerely,