just to share my experiances with this conversion (well worth it)i have a 56 f100 by the way
1 - the mounting bolts on the truck were 9/16" holes on the bell were 1/2" these were drilled out
2 -the dust cover that fits to the bottom of the bell has a small threaded nut welded to it the corresponding hole in the bell is also threaded and needs to be clearanced. this is because of the proximity of the oil pump.
3 - this one is down to me i think, i used a TCI converter and tig welded the studs as per instructions. they must have moved as i had problems mating up to flex plate. sort this out on the bench it's a swine to figure out on your back under the truck
i used an FE starter and have had no problems
there's a good article on this conversion on this website by Jeff Hallam
stuey