Engine trouble

[psmall000]

Hi guys, new here. I have a '69 LW with a 350 bored .060, flat top pistons,truck heads and a mild cam. I can't seem to get it running. The issue is when I turn it over it coughs and sputters and won't stay running. I have timed it 3 or 4 times and I am 90% sure its timed correctly. The last time it ran before I gave up, it bent pushrods and pitted brand new lifters. I thought maybe it was 1) Accidentally built too much compression in the engine and not enough octane, or 2) the rocker arms are the wrong ratio. I know it's not the valve adjustment, that is set to factory specs (according to Haynes).