Exhaust heat shields

[jl8z28]

I have NOS exhaust heat shields GM part number 458628 does anyone know what they are for thanks

[rszmjt]

Can you post a picture

[Mr70]

That short 4 series part number says late 1970's to me,maybe even early 80's.
..and here they are. https://www.ebay.com/itm/NOS-OEM-Spark-Plug-Heat-Shield-V8-Small-Block-Chevy-1976-82-/232587643529?_trksid=p2349526.m4383.l4275.c1#viTab s_0