273 Rocker Arm to Shaft Clearance

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 seems wide at .003" total. The rocker arm bores are consistent across all 16 and are not out of round. The shaft measures the same diameter where the rocker arms ride and at the towers. Because of no noticeable wear and confirmed low miles on the assemblies, it looks like the factory clearance was or was close to .003".

When I have the shaft in a vice and rock the arm straight against the shaft (not twisting but rocking to check clearance), there is noticeable play from the .003" clearance.

My question: Is this .003" clearance acceptable for a 6,500 rpm 450 HP build, or should I be looking to have the rocker arms bronze bushed and honed to the shaft, which will be far cheaper than a quality set of roller rocker arms. If they do need bushing, what is an ideal clearance? Thanks for any input.