OEMs gave up on flat tappet cam tech back in the 80s. Not really sure why anyone would use ancient tech in a build now. So many street friendly roller profiles out there to choose from. I lost a Comp solid flat tappet years ago...yes I did everything right, break in, springs, Brad Penn oil, etc. Put a Comp street solid roller in it and never looked back. Runs fantastic! Should have done the roller in the 1st place would have saved me $$$$ and headache. Live and learn.