You will need a BFH and go a little nuts on the trans tunnel where it and the firewall become one. My Pinto has a C5 with the 164 tooth flywheel although i'm using a C4 bell and flywheel (C5 bell is longer to accomadate the lock up torque convertor)
Back in '90 or '91, (before I knew anything about my II's special bell and flexplate) I bought a parts 68 cougar with a nice running 4bbl 302 and very solid-shifting C4.(I later discovered "C8P" on the valve body, which I assume means 1968 police unit)
Anyway, my II had stock exhaust manifolds back then, and I simply installed the 302/C4 right out of the cougar into the II without ever breaking the powertrain apart. (I may have swapped the oil pan first, but I'm really not certain)
I noticed things were very tight, but it fit without any mods at all. I later attempted to install headers, and they wouldnt fit. Heh. That's when I discovered there was a special bell/flexplate/converter/engine oil pan for the IIs. (Luckily, I'd kept all the old pieces in the shop)
I bet with a set of those strut-rod eliminators installed, and that damn factory strut-rod bracket/brace setup gone, headers and large bell wouldnt be an issue anymore.