I am currently restoring a '70 LS-6 manufactured April 4th and is a Kansas Plant car. What SS center caps are correct for that date, the screw on version or snap in canters?

My Kansas City (Leeds), MO '70 L34 equipped car came with the snap-in SS wheel center caps. Car was built 2nd week of Jan 70 (01B build date). I don't know when the SS center caps were changed over to the 3 bolt SS cap retainer type, but this only gives you at least a general timeframe. I have 2 original snap-in caps, and just recently bought another at Super Chevy Denver for $25. Still need 1 more. I've already purchased 4 NOS retainer type caps to replace them which can possibly thwart thieves efforts to steal them.