A lead tech told me to stop setting valve lash by feel, and he was dead right
I ran lash on a 12 valve Cummins by feel for a long time and swore it was close enough until a guy with 20 years on me said my "feel" was costing me 2 thousandths on the exhaust side. I bought a dial indicator and checked cold the way he wrote it on a card for me, and sure enough I was off. Anyone else get called out like that and switch their whole setup over?