Heres my advice. You dont have 2 drivers side mounts, you have 2 passenger side mounts. That's fact. I have been messing with this **** longer than I care to remember. See pic below. Pic is NOS pair of 67-72 V8 mounts. See the one circled. Thats what a drivers side bracket looks like. Has 3 block mounting holes. You have 2 of the one on the right. Passenger side brackets. Get a drivers side 67-72 A body 273 , 318 mount which is circled in the pic.
The 273 318 drivers side bracket is more readily available than the 340 , 360 and then just spacer the aft ear. Then it's a bolt in, and engine sits level. Then sell off the extra RH mount. These parts in the pic below are not mine. Just found em doing a quick search on fabo to give you an idea what to look for.
If you dont want to find a proper LH mount, then install the one on the right side of the engine, put the rubber mount on the mount bracket, oriented like I showed you in the OEM holes, not the ones you drilled. Set the engine in with "only" the RH mount on the block and a jack with a plywood square under the oil pan, and level it side to side, then mod your LH mount from the block down to the K Frame. Hope you know how to weld.
I'm out. I gave more than enough advice. Please listen to it to prevent chasing your tail around your shop even more than you already have.
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