Bolt strength question
I made some shackle mount brackets to go on the rear of my '86 chevy pickup that I am building for a trail rig. They are setup to use the 3 factory mounting holes for the stock rear bumper, (which has been removed) plus one more that I will have to drill. My question is will 4 - 1/2" diameter Grade 8 bolts be strong enough to hold up to the stress of pulling a full size rig out if it is stuck? Thanks in advance for your help.