I'm getting ready to put on a Harmin Marine engine mount and the size of these 5/16 timing cover bolts seem very twinkie.

I measured a depth of between 5/8 and 11/16 of threads and about 3 1/2 overall length under the head of the bolt. So I'm looking at getting some 4 inch length stainless socket cap and cutting each one down to get max threads with a washer and lock washer.
What seems messed up is the holes through the motor plate and the timing cover have what I consider a lot of play.

It almost looks like it could call for a special shouldered bolt to take out the extra movement.
Just wondering what everyone else has been using on their BBF front mounts?

What about studs with a beefier thread at the cover?

Do they make them?
And what would be a good torque spec on the motor plate?