I've installled quite a few 235/261 engines in the following manner;one end the the chain is bolted to the head on rear right using a home made steel plate bolted to the two 5/16 threaded holes for the coil, one 3/8 bolt securing the chain end to this bracket, and the front is secured to either a water pump bolt, or using the generator bracket bolt hole. Just one 3/8 bolt at the front, using a leveller with the two short pieces of DOT rated chain, and the bolts I use are grade 5 or whatever is laying around the shop,lol.The chains that come with the leveller are common non test chain generally. I do a lot of rigging at work using chainfalls and such to position large heavy electrial components in place, weighing many tons in some cases.A length of common low strength grade 2, 3/8 inch threaded rod is capable of supporting over 500 lbs according to engineering charts.I have personally used a single grade 5 ,3/8 bolt to secure the ends of a chain supporting over 1000 lbs as the equipment is lowered into place. Of course I stand clear using a tag line to guide the equipment into place as it's lowered.Our electrial winches used to pull large wires into conduit have torque meters on them, I have seen readings in excess of 5000 lbs of pulling force, the pulling rope secured to the wire ends using a clevis with a single 1/2 inch threaded forged pin.When pulling a junk engine,I just wrap the chain around the rocker arm shafts, very crude.
It's always good to be on the safe side when pulling a heavy engine,the head bolts certainly won't break, but I don't like to loosen head bolts on an engine I just spent time on making sure all the head bolts were torqued properly in sequence.At any rate, never put your hands in a position where the engine could crush you if it slips no matter how you rig it.
