Well... after assembling this other engine (after learning the TJ short block wont work well in my XJ), on a hunch, I checked the pushrod length - it seemed like there was excessive preload on the hydraulic lifters. Turns out, they were 0.200" too long.
I figure this difference is from the aftermarket (Hesco) head, and roller rockers. Either way, the correct rods are in the mail.
#engine #jeepxj #jeep40l #jeep #xj