7/16 sounds about right since it's a 9/16 bolt head if I recall correctly ... you'll need two different lengths ... I used Grade 8 from Ace Hardware on mine ...
Not sure, just bought mine last weekend, carried an old one with me. I bought all the same length, 1 1/2"long, mine have a 5/8 head....
Is that an FMX bell? or is it from the older Cast Iron Cruis-o-Matic? I am too lazy to go downstairs and check - I have got a few C4's laying around....
Nah ... that's just a picture of a small block Bellhousing I found on the web .... not a stick shifter bell though ... definitely an automatic ...
7/16th's x 1 3/4 should work fine for all holes. Use grade 5 or better and I would even put a dab of Loctite on them.