I've looked in five different factory and general service manuals spanning from 1957 (the LA273 shares a similar rocker arm as the A-block exhaust) to 1966 and cannot find any mention of or spec for rocker arm to shaft clearance. I have a pair of factory 1965 273 forged rocker arm assemblies with 30K original miles on the engine that I'd like to run if possible. Aside from the rocker arm tips and the thrust side of the shaft being polished from use, I find no wear. However, the clearance...
273 Rocker Arm to Shaft Clearance
