I can't figure it out, maybe you can?

I did replace all of the valve springs when I repaired it the first time.
I also checked to make sure that none of the valves were bent.
I'm pretty sure the lifters are the problem.
I ran the old valve springs a little to long but the inside of that engine looks like new, I checked everything when I had the heads off.

I'd like to build a stroker motor for it but it "ain't in the budget" this season.