The heads look like they're not flat in the center, and depending on how hot you got it, you may have damaged the rings, which is another reason it won't start easy. Make sure you tap the head bolt holes and chase the threads on the head blts, verify the deck is flat, and I'd have the heads milled to make sure they're flat. I use 30wt oil on the threads, and torque in 3 steps.
Also - your tune up might need some attention. The timing doesn't seem right, nor does the mixture.
