This guide is for people that are converting a 1966-1970 Ford falcon from a 6cyl to a V8.
For starters you can put anything from a 260-351w into the falcon without much issue.
First you will need the motor frame mounts from a v8 car, 66-69 Falcon, Fairlane, Comet, Ranchero, Torino all V8. They are bolted in with 4 bolts per side. The factory 6cyl mounts unbolt and the v8 mount bolt right in without any issues. These mounts can be bought from 50.00-100.00 and they are not reproduced.
You will also need the accelerator pedal assy. This is the part that bolts to the firewall using 3 screws the 6cyl in longer as it runs along the firewall over to the passengers side. The v8 is only on the drivers side. If you are running an automatic you need the assy with the kick down rod attached, otherwise you can remove it if you are doing a 4 speed.
Transmission cross members are the same for all small blocks,
Also the only issue you will have if you put in a 351w is the exhaust manifolds or headers as they will hit the steering box because of the larger width of the 351w.
Also if you swap out the motor to a v8 you will want to change the rear end to an 8 inch or 9 inch, big issue is the 66-70 Falcons have a certin size as no other car has so a perfect fit is a factory v8 falcon rear end. Early mustang will work but are smaller and the spring perches will need relocated.
Hope this helps......