I have a 2000 d16y7. Eagle rods, 9:1 srp pistons(.040 ptwc), head studs, ect. Head is stock with almost 200K. Bottom end has about 70K miles since build. The first build was done after it spun a rod bearing. That was a loud clacking sound even at idle. There were lots of gold flakes in the oil pan too.

Now I have another knocking sound. I've been tuning the engine on megasquirt. I have turned up the boost to about 10 psi from 8 psi and upped the rpm to 7200 for a few tests. Everything seemed ok but the power was lacking at that high rpm on this head. The next morning I noticed the engine rattle under mild acceleration. It sounded similar to the dreaded rod knock that prompted the build before. Idle isn't noticeable but revving the engine brings it on again. The more load on the engine the more pronounced the sound.

Today I did a compression test, removed the oil pan, and the head. Engine was dead cold with open throttle and 10 cranks each. 145, 144, 150, 155 I found nothing in the oil pan but clean oil. I jiggled the rods by hand and couldn't feel anything different between them. I pulled the head and removed the pistons. Nothing I could tell. The cylinder hone marks still show on the cylinder walls. A bit of vertical scuffing on the walls from the piston skirts is all. There was a bit of scuff on the crank bearing surface from top dead center to almost bottom. I don't think that's abnormal. The head looks good for as many abused miles as it's run. Valve lash was within tolerance.

Since there isn't any noticeable damage anywhere I can't find the problem. What should I check?