Slick 60's

I am about to install the new Small Block Ford engine perches in my 1966 F-100 for the new 351W. I just removed my I-300.
Now that i removed the old I-6/FE perches, I wanted to know ANY of the mounting holes for the Small Block perches/pedestals are the same. (top 2? bottom two?) I did visit the FORDIFiCATION website to see the pedestal differences, but they dont mention the mounting holes. how did ford do it?
if no holes were reused, does anyone have measuments?
thanks
cosmo

I removed the I-6 mount bolts and 3 of the 4 holes on each lined up with the V-8 perch holes so I only had to drill one hole for each perch in the frame crossmember to bolt them in with 4 bolts each. I did have to slightly enlarge the slotted pear shape hole on the upper end of the perchs for the rubber motor mount bolts to properly align the engine (output drive shaft of the transmission in alignment with the input flange of the rear axle) after I installed the engine/transmission in the truck.

What tranny are you using, Cosmo? If it is the original, I would recommend that you install the trans on the rear mount, and reference your perch holes based on that to determine where the perch holes line up, and where you need to drill. I'm doing a 97 5.8L EFI with an E4OD in my 66, so I'm not much help, as the E4OD is about 7 inches longer, and I've had to relocate the tranny mount rearward. Headers have been a PITA, too!

I've drilled several holes in the crossmember, but I don't remember which ones! I think at least one hole at the top worked, maybe two. I believe the small block perches will be moved rearward 2 inches when compared to the original I-6 perches I had when I am finished. I know there are others here who have done this, and I think they did it differently than I.

If your transmission is meant for a 65-79 F series, and you mount it in the stock location, to get a baseline for your perches, you also won't need to change the length of the driveshaft, either.

HTH