Opinion wanted...garage hoist hookup...

I want to know what you guys think about this. I have this 1/4" plate steel to come down off of 3 - 2"x10"'s in my attic into the garage. The bolts I want to use are 3/8" - 6" long. Do you guys think the 4 holes will weaken the 2"x10"'s to much? Or do you think the bolts will be strong enough? I want to be able to pull a motor (and tranny?) with it. How much do you think the beam is good for? It is 14' long and it sits on top off the garage walls. thanks

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