Bell Housing Bolt Size?

when i need to determine the size of a bolt etc, i use my tap and die set to test fit until i find the one that is correct. it saves multiple trips the nut and bolt store and i can zero in on the exact diameter and thread pitch i need.

In the MT-97 the illustration keys 2 bolts,in the listing 4 of one & 2 of the other are used. It doesn't specify what the bolts are for but it's kinda obvious to me. They have just IH #'s,no sizes but under each pn...washer,lk 7/16.
It's likely 7/16-14 course thread(?) Fine thread is 7/16-20. "Standard" wrench size for 7/16 is 11/16.

I made a fairly complete set of testing bolts for my friend Patricia. I stamped the size and TPI on the tops and included a nut with each bolt.
Our local PACIFIC FASTENERS offers complete plastic size test fixtures.
If you find yourself working on very old machinery, it might be a very good idea to check thread count. Don't assume anything. There was a time before standard sizes were agreed on where OEM fasteners could be anything the manufacturer wanted.
I have a few early 1900's flywheel engines with special bolts. I just finished restoring an early WF and John Barnes 22 inch drill press. There is nothing standard on this unit. I had to make some of the bolts and turn one replacement shaft that was 11/16" with smaller end s for the keyed and pinned gears on each end.

BTW:
For those who don't have a vernier caliper, try using an adjustable CRESCENT WRENCH, MADE IN USA, To measure the outside of a bolt then measure the opening of the wrench while it is still on the bolt body. Many adjustable wrenchs have some slack which may throw off a measurement if removed.
Many tool stores offer acceptable plastic vernier calipers for a few bucks and sometimes free as a promotion.

See that? Even a simple question like I asked generated all sorts information and ideas that didn't think of! Thanks everyone!

I will be mounting that motor tonight. It takes 7/16 inch, course thread bolts.

Pete