ZR1 is a Corvette. VR1 is a Valvoline oil.

Uhh you might want to read section 1 of a few FSM's form "back in the day"

Short answer to the OP's question: I would, and it won't hurt anything if somehow it's overkill.
I like to stack the cards in my favor, so to speak, and so far that's paid off.

I started drag racing in the '60s, and paying attention to oil, and there were indeed different weights & of course brands; non-detergent was available but not popular, and was pretty much an oddity.
ZDDP & phosphorous were reduced from previous levels in the mid-90s. So yes, there was more of both previously.
IIRC, that was an emissions deal, maybe for catalytic converter efficiency ? Sulphur in diesel fuel was also reduced for the cats.
The newer vehicles were switching to roller lifters, or had already, so the levels for FT stuff were de-prioritized.

Really.

will changing brand of oil in a running engine [after a cam change only] do damage ?
engine in question has been running amsoil, and the change is to valvoline.

Video boroscopes and laboratory oil analysis are now relatively cheap,
but rebuild labor is more expensive.

For flat tappet applications maybe turn attention to how to inspect with a small diameter head video boroscope with minimum teardown, like maybe a tapped inspection hole that can be closed with a plug.

Lab oil analysis on new oil, then at 500 miles?

For large expensive tapered roller bearings “break in” for industrial applications
Torrington used to advise using a heavier, higher viscosity oil
pre-warmed to 30 degrees above expected operating temperature prior to initial start,
then changed at 48 hours.

Really. [/quote]
REALLY !!
From a 1970 FSM section 1 pages 15 and 16

Summit sells Lucas brand break in oil. $27 for a 5 qt jug. Cheap insurance.
Doug

^^this. One of the biggest differences between break in/racing oil vs street oil is that the street oil has detergents in it.

I run the engine for break in, how you break it in is a whole different subject, then change oil. More often than not to a different brand/type and no extra additives outside of anti-wear additives for a normal engine, usually none. i.e. break in with 30w conventional or break in oil and switch to 10w-40 synthetic at 500 miles.

Never had a problem.

Over the long haul I find it more important to change frequently and use a good brand. Clean oil is more important than the brand but the brand does have a definite effect over the long term. IMHO