Thanks, (sorry I haven't logged-in in a while)

I think I'll try and stay with the XE256 for a while. Mostly because I really don't feel like pulling the front of the engine apart again. And it sure has great torque down low. For what I do that's where I need it. It's rare I hit 4000rpm.

I disassembled the first two lifters tonight. I think I'm finding my problem. I couldn't believe all the crap inside them. Which is hard to believe given how much I scrubbed the block before assembly. Including running rifle brushes through all the oil galleys. The #1 intake lifter had a couple of good sized chunks of something in it. Also the disc was galled where it meets the lifter plunger. I turned it upside down on reassembly.

Also I noticed the pushrods on #5 are just barely hitting the lower edge of the hole through the heads at full lift. There are some nice marks on the pushrods. They don't seem to be bent. I'll have to carefully clearance the hole a little more. I'll also check the lifters closely. Hopefully nothing's damaged. That could be contributing to some of my woes.

However if I install a cam with higher lift I'm going to have to enlarge all the pushrod holes through the head. I have the small hole, stud mounted rocker heads.