Got fuel, spark, comp but no start

My 86 ram with a freshly rebuilt 408 refuses to start. Its been on ongoing issue with both the mopar ignition and now with the msd 6al. The old teener it replaced ran fine, well, never a no start issue that is.

I have 170 in every hole, got fresh gas (ether too), good strong spark, but no boom.... I tried adv/rtd the timing but nothing. I even advanced it to the point that it was kickin back on the starter.

One thing I will mention, is it did this a couple weeks ago, couldn't figure it out. Then as last resort, I decided to try advancing the dizzy, wouldn't you know it, it fired right up. Now I was sure the dizzy was tight, but I thought maybe at high rpm harmonics loosened er up. Once I got it running, I warmed it up, reset the timing @ 19°, played with the mixture screws a bit, had it running great and then out of no were it dies. Like it was starving, try to feather it, but no luck. It'd start right back up and run/rev just fine. Then 3-4min later it'd do the same thing. I was tired and called it a night.

Now I've returned and the bloody pig won't even start not even a stumble, nothing :wack:

Anyone got some ideas? Im beginning to think I built a 4th element motor, I just don't know what that 4th element is. It ain't gas/air/spark cuz its got plenty of that. :banghead: