I used a 360 flywheel when i swaped my 400 to a 460. I've used both types of clutches with no problem at all. I used a three finger clutch for the first swap. When that engine blew I went to a diaphram clutch for the second swap. I did have to have a pilot bearing machined and i used two engine backing plates. It's my daily driver with over 40,000 miles since the swap with no problems.

Hyperactive460

 

 

When I did a 4spd swap in a old 77 F-350 I used a 390 Flyhwheel and a 11" clutch the 11.5 clutch will not fit the 351M bellhousing I found out the hard way. The 11" clutch isn't strong enough behind the 460 I had my clutch slip in first gear when I was pulling on something heavy. The 4spd swap was well worth it I did have to make a 1/2 thick plate to go between the bellhousing and the transmission spline as the crank snout on a 460 sticks out farther. I used the truck for a year or so with the 4spd swap and all the different parts that was required todo the swap worked fine I never had any bearing problems. The only hard part was trying to get a starter to fit the one that worked was off of a 400 with a automatic transmission the one off of the 460 didn't work.