looking Great!
I have a 4.3 in my mazda b2200 ex-cab too. I need to redo the motor mounts in my truck. They are way messed up and i like the look of yours. Can you IM me and give me some details of things you did, parts you got ect?
Use late '70's car engine mounts. They will be right over the original pads on frame, simply make a "u" shaped saddle for them. Bolt to the engine, sit engine down on the pads, mark the place to drill the holes in the saddles. Lift engine, pull bolt out holding the saddles to the engine mount, drill the holes where marked, bolt in, done.
So you ended up using a lower poly mount,and bolted it to the block,and built brackets from the frame to those?