243 vs 01 ls6 heads

[r.barn]

well the LS6 heads have hte lighter and longer valves. other forms of the 243 have standard valves

both flow same

Only the 02's have the lighter valves.

01 LS6 heads had regular 243 valves with weaker "Blue" springs.

02 got the light valves and yellow springs and LS2 243's got the
yellow springs too.